Nutrition- Carbohydrates Meal Plan, science homework help

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Please submit Meal Planning for Carbohydrates Assignment here.

Part A

Please respond to the following questions in complete sentences and paragraphs. This section should be at least 200 words.

  • What is meant by the AMDR, and what is this range for carbohydrates?
  • How does the type of carbohydrate impact health?
  • What is one negative health impact from carbohydrate intake?
  • What is one positive health impact from carbohydrate intake?

Part B

Here is a sample one-day menu for Mr. Brown. His doctor just told him to cut down on added sugars in addition to increasing his fiber intake. He hopes to meet with a dietitian next week, but in the meantime needs some help making these changes. List five suggestions for Mr. Brown’s diet. Make sure to provide only changes that address the meal planning goals mentioned above. Tell him which food(s) you would have him omit and how you would replace these items. You may also change portion sizes. Highlight (yellow only, please) or bold the item you are changing. Then write the change next to that. You may make more than five changes, but if you do so, you will only receive full credit when all changes correctly match the assigned directions.

Breakfast
1 cup sugar-frosted flake cereal
8 oz 1% milk
8 oz orange juice
2 scrambled eggs

Snack
1/2 peanut butter and jelly sandwich (1 slice white bread, 1 TBSP Skippy peanut butter, 1 TBSP grape jelly)

Lunch
8 oz tomato soup
6 Saltine crackers
1 turkey sandwich (3 oz turkey, 2 slices white bread)
1/2 cup canned pears in heavy syrup
8 oz grape juice

Snack
6 oz fruited yogurt, sweetened
1 oz almonds

Dinner
5 oz BBQ chicken
1 medium baked potato with 1 TBSP butter
1/2 cup cooked broccoli
8 oz cola
4 oz 1% milk

Snack
1/2 cup chocolate ice cream

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An Introduction to Nutrition v. 1.0 An Introduction to Nutrition is available under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported license without attribution as requested by the site’s original creator or licensee. This is the book An Introduction to Nutrition (v. 1.0). This book is licensed under a Creative Commons by-nc-sa 3.0 (http://creativecommons.org/licenses/by-nc-sa/ 3.0/) license. See the license for more details, but that basically means you can share this book as long as you credit the author (but see below), don't make money from it, and do make it available to everyone else under the same terms. This book was accessible as of December 29, 2012, and it was downloaded then by Andy Schmitz (http://lardbucket.org) in an effort to preserve the availability of this book. Normally, the author and publisher would be credited here. However, the publisher has asked for the customary Creative Commons attribution to the original publisher, authors, title, and book URI to be removed. Additionally, per the publisher's request, their name has been removed in some passages. More information is available on this project's attribution page (http://2012books.lardbucket.org/attribution.html?utm_source=header). For more information on the source of this book, or why it is available for free, please see the project's home page (http://2012books.lardbucket.org/). You can browse or download additional books there. ii Table of Contents About the Authors................................................................................................................. 1 Acknowledgments................................................................................................................. 3 Dedications ............................................................................................................................. 4 Preface..................................................................................................................................... 5 Chapter 1: Nutrition and You ............................................................................................. 9 Defining Nutrition, Health, and Disease .................................................................................................... 12 What Are Nutrients? .................................................................................................................................... 18 The Broad Role of Nutritional Science....................................................................................................... 26 Health Factors and Their Impact................................................................................................................ 36 Assessing Personal Health........................................................................................................................... 50 A Fresh Perspective: Sustainable Food Systems ....................................................................................... 55 End-of-Chapter Exercises ............................................................................................................................ 63 Chapter 2: Achieving a Healthy Diet ............................................................................... 65 A Healthy Philosophy toward Food............................................................................................................ 69 What Is Nutritional Balance and Moderation? ......................................................................................... 74 Understanding the Bigger Picture of Dietary Guidelines ........................................................................ 82 National Goals for Nutrition and Health: Healthy People 2020 .............................................................. 88 Recommendations for Optimal Health ...................................................................................................... 95 Understanding Daily Reference Intakes .................................................................................................. 101 Discovering Nutrition Facts ...................................................................................................................... 106 When Enough Is Enough............................................................................................................................ 115 Nutrition and the Media............................................................................................................................ 119 End-of-Chapter Exercises .......................................................................................................................... 123 Chapter 3: Nutrition and the Human Body ................................................................. 125 The Basic Structural and Functional Unit of Life: The Cell ................................................................... 128 Digestion and Absorption.......................................................................................................................... 134 Nutrients Are Essential for Organ Function............................................................................................ 142 Energy and Calories ................................................................................................................................... 152 Disorders That Can Compromise Health ................................................................................................. 156 End-of-Chapter Exercises .......................................................................................................................... 163 iii Chapter 4: Carbohydrates ............................................................................................... 165 A Closer Look at Carbohydrates ............................................................................................................... 169 Digestion and Absorption of Carbohydrates ........................................................................................... 176 The Functions of Carbohydrates in the Body.......................................................................................... 188 Looking Closely at Diabetes ...................................................................................................................... 194 Health Consequences and Benefits of High-Carbohydrate Diets .......................................................... 202 Carbohydrates and Personal Diet Choices............................................................................................... 212 The Food Industry: Functional Attributes of Carbohydrates and the Use of Sugar Substitutes .......219 End-of-Chapter Exercises .......................................................................................................................... 231 Chapter 5: Lipids ............................................................................................................... 233 What Are Lipids? ........................................................................................................................................ 236 How Lipids Work ........................................................................................................................................ 243 Digestion and Absorption of Lipids .......................................................................................................... 252 Understanding Blood Cholesterol ............................................................................................................ 257 Balancing Your Diet with Lipids ............................................................................................................... 263 Lipids and the Food Industry .................................................................................................................... 268 Lipids and Disease ...................................................................................................................................... 272 A Personal Choice about Lipids ................................................................................................................ 276 End-of-Chapter Exercises .......................................................................................................................... 281 Chapter 6: Proteins........................................................................................................... 282 Defining Protein ......................................................................................................................................... 285 The Role of Proteins in Foods: Cooking and Denaturation.................................................................... 293 Protein Digestion and Absorption............................................................................................................ 296 Protein’s Functions in the Body ............................................................................................................... 300 Diseases Involving Proteins ...................................................................................................................... 308 Proteins, Diet, and Personal Choices........................................................................................................ 314 End-of-Chapter Exercises .......................................................................................................................... 333 Chapter 7: Nutrients Important to Fluid and Electrolyte Balance ......................... 335 Overview of Fluid and Electrolyte Balance.............................................................................................. 338 Water’s Importance to Vitality................................................................................................................. 342 Regulation of Water Balance..................................................................................................................... 346 Electrolytes Important for Fluid Balance ................................................................................................ 354 Consequences of Deficiency or Excess ..................................................................................................... 373 Water Concerns .......................................................................................................................................... 378 Popular Beverage Choices ......................................................................................................................... 389 End-of-Chapter Exercises .......................................................................................................................... 402 iv Chapter 8: Nutrients Important As Antioxidants ...................................................... 403 Generation of Free Radicals in the Body ................................................................................................. 406 Antioxidant Micronutrients...................................................................................................................... 413 The Whole Nutrient Package versus Disease .......................................................................................... 438 End-of-Chapter Exercises .......................................................................................................................... 444 Chapter 9: Nutrients Important for Bone Health ...................................................... 445 Bone Structure and Function.................................................................................................................... 448 Bone Mineral Density Is an Indicator of Bone Health ............................................................................ 455 Micronutrients Essential for Bone Health: Calcium and Vitamin D ..................................................... 457 Other Essential Micronutrients for Bone Health: Phosphorous, Magnesium, Fluoride, and Vitamin K ................................................................................................................................................................... 473 Osteoporosis ............................................................................................................................................... 484 Risk Factors for Osteoporosis ................................................................................................................... 488 Osteoporosis Prevention and Treatment ................................................................................................ 493 Deficiency, Supplementation, and Choices ............................................................................................. 498 End-of-Chapter Exercises .......................................................................................................................... 505 Chapter 10: Nutrients Important for Metabolism and Blood Function ................ 507 Blood’s Function in the Body and in Metabolism Support .................................................................... 509 Metabolism Overview ................................................................................................................................ 516 Vitamins Important for Metabolism and for Blood Function and Renewal ........................................ 523 Minerals Important for Metabolism and for Blood Function and Renewal......................................... 537 Iron-Deficiency Anemia............................................................................................................................. 545 End-of-Chapter Exercises .......................................................................................................................... 552 Chapter 11: Energy Balance and Body Weight............................................................ 553 Indicators of Health: Body Mass Index, Body Fat Content, and Fat Distribution................................ 557 Balancing Energy Input with Energy Output .......................................................................................... 562 Too Little or Too Much Weight: What Are the Health Risks?................................................................ 575 Dietary, Behavioral, and Physical Activity Recommendations for Weight Management ..................581 End-of-Chapter Exercises .......................................................................................................................... 589 Chapter 12: Nutrition through the Life Cycle: From Pregnancy to the Toddler Years .................................................................................................................................... 591 The Human Life Cycle ................................................................................................................................ 594 Pregnancy and Nutrition........................................................................................................................... 598 Infancy and Nutrition ................................................................................................................................ 614 Nutrition in the Toddler Years ................................................................................................................. 632 End-of-Chapter Exercises .......................................................................................................................... 641 v Chapter 13: Nutrition through the Life Cycle: From Childhood to the Elderly Years .................................................................................................................................... 643 The Human Life Cycle Continues.............................................................................................................. 646 Childhood and Nutrition ........................................................................................................................... 651 Puberty and Nutrition ............................................................................................................................... 659 Older Adolescence and Nutrition ............................................................................................................. 665 Young Adulthood and Nutrition............................................................................................................... 670 Middle Age and Nutrition ......................................................................................................................... 676 Old Age and Nutrition................................................................................................................................ 681 End-of-Chapter Exercises .......................................................................................................................... 687 Chapter 14: Nutrition and Society: Food Politics and Perspectives....................... 689 Historical Perspectives on Food ............................................................................................................... 692 The Food Industry...................................................................................................................................... 699 The Politics of Food.................................................................................................................................... 708 Food Cost and Inflation ............................................................................................................................. 714 The Issue of Food Security ........................................................................................................................ 718 Nutrition and Your Health ........................................................................................................................ 726 Diets around the World ............................................................................................................................. 732 End-of-Chapter Exercises .......................................................................................................................... 744 Chapter 15: Achieving Optimal Health: Wellness and Nutrition ............................ 746 Diet Trends and Health.............................................................................................................................. 749 Fitness and Health ..................................................................................................................................... 763 Threats to Health ....................................................................................................................................... 770 Foodborne Illness and Food Safety .......................................................................................................... 782 Start Your Sustainable Future Today....................................................................................................... 797 Careers in Nutrition................................................................................................................................... 802 End-of-Chapter Exercises .......................................................................................................................... 806 Chapter 16: Appendix A ................................................................................................... 807 vi About the Authors Maureen Zimmerman Dr. Maureen Zimmerman earned her undergraduate degree in Nutrition and Dietetics at Arizona State University, a Master’s Degree in Public Health from the University of Hawaii, and a Doctorate in Educational Leadership, with a specialization in educational research, from Northern Arizona University. She is a Registered Dietitian and has been a residential faculty member at Mesa Community College in Mesa, Arizona since 1991. She has been involved in many aspects of college life, most of them related to improving teaching and learning. She works indefatigably to assure that students enjoy their learning journey, regularly applying learning science to the online and ground classrooms. She is active every day of the week either practicing yoga, biking, hiking, tap dancing, or running. She enjoys reading a variety of genres, and likes to drink good coffee in the company of friends and family. She watches international films regularly, and tries to eat many fruits and vegetables every day. Her food first philosophy is summed up in this statement: “Enjoy real food, enjoy it with others, enjoy it in just the right amounts.” Beth Snow Dr. Beth Snow earned a BS (Hons) in Biochemistry (with a minor in Drama) from McMaster University in 1999, an MS in Human Biology & Nutritional Sciences from the University of Guelph in 2000, and a PhD in Human Nutrition from the University of British Columbia in 2006. She also holds a Credentialed Evaluator designation from the Canadian Evaluation Society. Her PhD research focused on the effects of prenatal alcohol exposure on the developing fetal skeleton and she has published in the journals Bone, Alcohol, and Alcoholism: Clinical & Experimental Research. Following her PhD training, she spent two years working at the British Columbia Centre of Excellence for Women’s Health, where she ran an interdisciplinary research training 1 About the Authors program. She currently works as an Evaluation Specialist in Public Health in Vancouver, BC, Canada, where she also teaches at the University of British Columbia and the Justice Institute of British Columbia. Her teaching philosophy involves empowering students to take ownership of their own learning; she uses active learning techniques and encourages students to apply what they learn to real life. Being a lifelong learner herself, Beth is currently working on a Masters of Business Administration at the University of British Columbia, with the goal of combining knowledge about organizations with her health research expertise in order to help get research evidence into Public Health practice. In addition to her busy career, Beth is a true foodie who always makes time to cook and share good food and she enjoys hiking, running, yoga, and, being a Canadian, playing ice hockey. 2 Acknowledgments It takes a village to create a textbook and we are deeply indebted to all those who helped us make this book a reality. First and foremost, our deepest thanks go out to all those who reviewed our chapters and gave us thoughtful feedback on how to make them even better: • • • • • • • • • • • • • • • • Patricia Abraham, Arkansas State University Jessica Adams, Colby-Sawyer College Christine Bieszczad, Colby-Sawyer College Douglas Bruce, Laney College Kathleen L. Deegan, California State University, Sacramento Lindsay Edwards, Hardin-Simmons University Cathy Headley, Judson University Laura Hutchinson, Holyoke Community College Christa Koval, Colorado Christian University Beth Ann Krueger, Central Arizona College–Aravaipa Campus Patrick Mathews, Friends University Jill O’Malley, Erie Community College Ana Otero, Emmanuel College Alfred Ordman, Beloit College Paula Vineyard Most, John A. Logan College Linda Wright, Dixie State College of Utah We are especially thankful to Teresa Fung for her expert content editing. Teresa has a keen eye for scientific accuracy. Because she is steeped in the nutrition literature, her input has been invaluable. The development editors included Melissa Lingohr-Smith, Lisa Benjamin, and Danielle Dresden. We are also very grateful for the incredible support we received from the teams at Unnamed Publisher and The Research Masters. Melissa Yu of Unnamed Publisher and Amy Bethea of The Research Masters have provided such invaluable support in managing the creation of this book—it could not have happened without them. We would also like to thank Michael Boezi and all the others at Unnamed Publisher who have championed a nonmajors nutrition book. 3 Dedications Maureen Zimmerman Many people have shaped my professional and personal life. I would be remiss not to acknowledge those who saw potential and hired me in 1991 to develop a nutrition program at Mesa Community College. To those who initiated and maintained the stellar teaching and learning movement in the Maricopa Community College District, I am grateful. To my colleagues and the doctoral faculty who helped form my teaching practice, thank you. Succor comes from my family. My five children, in particular, experienced my nutritional philosophies even before the cradle. They brought hummus to school before it ever hit the grocery store shelves. Studying and teaching nutrition has been a fulfilling part of my life; I am grateful to all who have influenced me, most especially the thousands of students I have learned with through the years. Beth Snow I dedicate this book to my mother, Ann Snow, who taught me the fun of cooking, and my father, the late Jack Snow, who showed me the amazing world of biology. Marrying these two interests led to my pursuit of an education in nutritional sciences and, ultimately, to authoring this textbook. 4 Preface Welcome to Essentials of Nutrition: A Functional Approach! This book is written for students who are not majoring in nutrition, but want to learn about the fundamental aspects of nutrition and how it applies to their own lives. We have written this book with the assumption that you have little or no prior knowledge of college level chemistry, biology, or physiology. But that does not mean it’s not scientific! Nutrition is a science-based discipline, so all the material included is backed up by rigorous scientific research, but it is presented in a clear, easy-tounderstand fashion without requiring a background in science. Focus on Sustainability People are increasingly interested in sustainable food issues. They are looking for favorable ways to impact not only their health, but also the environment and their local economy. However, misinformation about how one can make a positive impact abounds. By highlighting effective sustainable food behaviors, supported by science, this book will provide you with a significant resource for increasing the sustainable practices in your day-to-day life. Organization This book is organized using a functional approach, which means that the material is organized around physiological functions, such as fluid and electrolyte balance, antioxidant function, bone health, energy and metabolism, and blood health, instead of organizing it strictly by nutrient. This makes the information easier to understand, retain, and apply to your own life. As this text explores the relationship between nutrition and physiology, you will receive a “behind the scenes” examination of health and disease in the body. • In Chapter 1 "Nutrition and You", we provide an overview of nutrition as an evidence-based science and explore the concepts of health, wellness, and disease. We also provide an introduction to the different types of nutrients, health factors, personal health assessment, and the concept of sustainable food systems. • In Chapter 2 "Achieving a Healthy Diet", we explore the tools you can use to achieve a healthy diet, as well as important nutrition concepts like balance and moderation. 5 Preface • In Chapter 3 "Nutrition and the Human Body", because we know that you may not have a background in biology, we start with a tour through the human body, from the single cell to the full organism, we set up for a discussion about the processes of digestion and absorption, followed by explorations of the other organ systems. After that, we discuss the concept of energy and calories. We also discuss some disorders and diseases related to nutritional health. • In Chapter 4 "Carbohydrates", we explore the many types of carbohydrates, including their functions. We also take a look at diabetes and at sugar substitutes. • In Chapter 5 "Lipids", we look at the types, structure, and roles of lipids, and we explain the different types of cholesterol in the blood. We also explore topics of interest such as omega-3 and omega-6 fatty acids and trans fats. • In Chapter 6 "Proteins", we cover the structure and roles of protein, and explore the consequences of getting too little or too much protein in your diet. Tips for getting the right amount and quality of protein, as well as a look at special populations, such as the elderly and athletes, are also covered. • In Chapter 7 "Nutrients Important to Fluid and Electrolyte Balance", we look at the nutrients important to fluid and electrolyte balance, including water, sodium, chloride, and potassium. We also look at sports drinks, caffeinated beverages, and alcohol. • In Chapter 8 "Nutrients Important As Antioxidants", nutrients important as antioxidants are explored, starting with an explanation of what oxidation and antioxidants are, then looking at vitamins E, C, and A, selenium, and phytochemicals. • In Chapter 9 "Nutrients Important for Bone Health", we delve into nutrients important for bone health. First, we explore the structure and function of bones, and then calcium, vitamin D, phosphorus, magnesium, fluoride, and vitamin K. A look at osteoporosis and at supplements rounds out this chapter. • In Chapter 10 "Nutrients Important for Metabolism and Blood Function", we look at the nutrients important in energy metabolism and blood health, by first looking at blood and at metabolism, and then discussing the B vitamins, vitamin K, magnesium, iron, zinc, and other micronutrients. We also explore iron-deficient anemia and iron toxicity. • In Chapter 11 "Energy Balance and Body Weight", we take a look at the obesity epidemic and eating disorders—the extremes of energy imbalance—and we look at evidence-based recommendations for maintaining a healthy weight. • Chapter 12 "Nutrition through the Life Cycle: From Pregnancy to the Toddler Years" is the first of two chapters exploring nutrition through 6 Preface the life cycle and it looks at pregnancy through the toddler years. Topics include pregnancy, breastfeeding, introducing solid foods, and nutrition during the toddler years. • In Chapter 13 "Nutrition through the Life Cycle: From Childhood to the Elderly Years" we continue to explore nutrition through the life cycle, this time looking at childhood to the elderly years. • In Chapter 14 "Nutrition and Society: Food Politics and Perspectives", we explore food politics, sustainability, the food industry, food security, and diets from around the world. • In Chapter 15 "Achieving Optimal Health: Wellness and Nutrition", we look at a number of topics of interest to students: diet trends, food supplements and food replacements, fitness, chronic diseases, and food safety. Also included in this chapter are tips for living a sustainable lifestyle, and information about careers in nutrition. Features Each chapter starts with a “Big Idea,” which provides a preview of the main theme of the chapter. You Decide challenges you to apply what you are learning about nutrition topics—sometimes controversial ones—to your own life. Key Takeaways and Key Terms provide the key take-home messages and definitions from each section, helping you to focus on the main points you should be learning. Discussion Starters are questions that can prompt discussions with fellow students and your instructor to examine and extend what you’ve learned in the chapter. There are many Videos available online and it is not always clear which ones have reliable information. We have done the legwork for you by providing interesting videos from reputable sources to accompany and highlight the content. Similarly, we provide links to useful online learning tools through the Interactive feature. Most of the databases for diet analysis programs primarily feature industrial food. As we promote sustainable food activities in our text, we cannot use these common diet analysis programs because they do not cater to students who eat real food prepared at home. As a result, we provide links to http://www.choosemyplate.gov/ throughout the text. You will be encouraged to create your own meals, shop 7 Preface smarter, choose wisely, and, at the same time, foster an active attitude toward food sustainability. Every chapter ends with Exercises, which are activities that can be used to test what has been learned in the chapter and may be used by your instructor as homework or assignment questions. There are exercises at three different levels (It’s Your Turn, Apply It, and Expand Your Knowledge) to meet the varied needs of different students. Please do not use this book to substitute for professional medical care or advice. If you have medical concerns or questions, always seek guidance from a health-care professional. The authors and publisher are not responsible for the accuracy of any content added by faculty. 8 Chapter 1 Nutrition and You Big Idea Nutrition is an evidence-based science. Nutritional scientists continuously advance our knowledge of nutrition by building on prior research. s t es r t h g Ima o m e re c o t e u d d e v ig r y op on i t c ri As we get started on our journey into the world of health and nutrition, our first focus will be to demonstrate that nutritional science is an evolving field of study, continually being updated and supported by research, studies, and trials. Once we establish this, your confidence will be strengthened in nutritional science to help guide your eating habits. Let’s begin with the story of hurry, curry, and worry: the story of H. pylori. Peptic ulcers are painful sores in the gastrointestinal tract and can cause symptoms of abdominal pain, nausea, loss of appetite, and weight loss. The cure for this ailment took some time for scientists to figure out. If your grandfather complained to his doctor of symptoms of peptic ulcer, he was probably told to avoid spicy foods, alcohol, and coffee, and to manage his stress. In the early twentieth century, the medical community thought peptic ulcers were caused by what you ate and drank, 9 Chapter 1 Nutrition and You and by stress. In 1915, Dr. Bertram W. Sippy devised the “Sippy diet” for treating peptic ulcers. Dr. Sippy advised patients to drink small amounts of cream and milk every hour in order to neutralize stomach acid. And then, increasingly, introduce soft bland foods with frequent meal times. For a while this diet sometimes worked, fooling both doctors and patients. However, the disappearance of peptic ulcer symptoms was likely the result of having a full stomach all the time, as the symptoms more often occur when the stomach is empty. Ultimately, the Sippy diet did not cure peptic ulcers and in the latter 1960s scientists discovered the diet was associated with a significant increase in heart disease due to its high saturated fat content. In the 1980s, Australian physicians Barry Marshall and Robin WarrenCurrey, R. “Ulcers—The Culprit Is H. Pylori!” National Institutes of Health, Office of Science Education. Accessed November 10, 2011. http://science.education.nih.gov/ home2.nsf/Educational+ResourcesResource+FormatsOnline+Resources+High+ School/928BAB9A176A71B585256CCD00634489 proposed a radical hypothesis—that the cause of ulcers was bacteria that could survive in the acidic environment of the stomach and small intestine. They met with significant opposition to their hypothesis but they persisted with their research. Their research led to an understanding that the spiral shape of the bacterium H. pylori allows it to penetrate the stomach’s mucous lining, where it secretes an enzyme that generates substances to neutralize the stomach’s acidity. This weakens the stomach’s protective mucous, making the tissue more susceptible to the damaging effects of acid, leading to the development of sores and ulcers. H. pylori also prompt the stomach to produce even more acid, further damaging the stomach lining. Marshall actually drank a dish of H. pylori hoping to give himself an ulcer to prove his point. A few days later he was vomiting and had inflamed tissue in his stomach. The presence of H. pylori was confirmed. He then took an antibiotic and the symptoms of H. pylori infection dissipated. Experimental success? It still took years for the medical community to be entirely convinced of the link between peptic ulcers and H. pylori. In 1994, the National Institutes of Health held a conference on the cause of peptic ulcers. There was scientific consensus that H. pylori cause most peptic ulcers and that patients should be treated with antibiotics. In 1996, the Food and Drug Administration (FDA) approved the first antibiotic that could be used to treat patients with peptic ulcers. Nevertheless, the link between H. pylori and peptic ulcers was not sufficiently communicated to health-care providers. In fact, 75 percent of patients with peptic ulcers in the late 1990s were still being prescribed antacid medications and advised to change their diet and reduce their stress. In 1997, the Centers for Disease Control and Prevention (CDC), alongside other public health organizations, began an intensive educational campaign to convince the public and health-care providers that peptic ulcers are a curable condition 10 Chapter 1 Nutrition and You requiring treatment with antibiotics. Today, if you go to your primary physician you will be given the option of taking an antibiotic to eradicate H. pylori from your gut. Scientists have progressed even further and mapped the entire genome of H. pylori, which will hopefully aid in the discovery of even better drugs to treat peptic ulcers. The H. pylori discovery was made recently, overturning a theory applied in our own time. The demystification of disease requires the continuous forward march of science, overturning old, traditional theories and discovering new, more effective ways to treat disease and promote health. In 2005, Marshall and Warren were awarded the prestigious Nobel Prize in medicine for their discovery that many stomach ulcers are caused by H. pylori—not by hurry, curry, and worry. You Decide Make a commitment to empower yourself with scientific evidence as a strategy for achieving a healthier diet. A primary goal of this text is to provide you with information backed by nutritional science, and with a variety of resources that use scientific evidence to optimize health and prevent disease. In this chapter you will see that there are many conditions and deadly diseases that can be prevented by good nutrition. You will also discover the many other determinants of health and disease, how the powerful tool of scientific investigation is used to design dietary guidelines, and recommendations that will promote health and prevent disease. “The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ but ‘That’s funny...’” - Isaac Asimov (January 2, 1920–April 6, 1992) 11 Chapter 1 Nutrition and You 1.1 Defining Nutrition, Health, and Disease LEARNING OBJECTIVE 1. Explain the terms nutrition, health, health promotion, and disease prevention. Your View of Food Americans are bombarded with television programs that show where to find the best dinners, pizzas, and cakes, and the restaurants that serve the biggest and juiciest burgers. Other programs feature chefs battling to prepare meals, and the top places to burst your belly from consuming atomic chicken wings and deli sandwiches longer than a foot. There are also shows that feature bizarre foods from cultures around the world. How do you use the information from popular network food shows to build a nutritious meal? You don’t—these shows are for entertainment. The construction of a nutritious meal requires learning about which foods are healthy and which foods are not, how foods and nutrients function in your body, and how to use scientific resources. This text is designed to provide you with the information necessary to make sound nutritional choices that will optimize health and help prevent disease. s t es r t h g Ima o m e re c o t e u d d e v ig r y op on i t c ri 12 Chapter 1 Nutrition and You The word nutrition first appeared in 1551 and comes from the Latin word nutrire, meaning “to nourish.” Today, we define nutrition1 as the sum of all processes involved in how organisms obtain nutrients, metabolize them, and use them to support all of life’s processes. Nutritional science2 is the investigation of how an organism is nourished, and incorporates the study of how nourishment affects personal health, population health, and planetary health. Nutritional science covers a wide spectrum of disciplines. As a result, nutritional scientists can specialize in particular aspects of nutrition such as biology, physiology, immunology, biochemistry, education, psychology, sustainability, and sociology. Without adequate nutrition the human body does not function optimally, and severe nutritional inadequacy can lead to disease and even death. The typical American diet is lacking in many ways, from not containing the proper amounts of essential nutrients, to being too speedily consumed, to being only meagerly satisfying. Dietitians are nutrition professionals who integrate their knowledge of nutritional science into helping people achieve a healthy diet and develop good dietary habits. The Academy of Nutrition and Dietetics (AND) is the largest organization of nutrition professionals worldwide and dietitians registered with the AND are committed to helping Americans eat well and live healthier lives. To learn more from the AND’s nutritional advice, visit http://www.eatright.org/ default.aspx. 1. The sum of all processes involved in how organisms obtain nutrients, metabolize them, and use them to support all of life’s processes. 2. The investigation of how an organism is nourished, and how nourishment affects personal health, population health, and planetary health. Your ability to wake up, to think clearly, to communicate, to hope, to dream, to go to school, to gain knowledge, to go to work, to earn a living, and to do all of the things that you like to do are dependent upon one factor—your health. Good health means you are able to function normally and work hard to achieve your goals in life. For the next few minutes, take some time to view snapshots of the insides of the refrigerators of American mechanics, doctors, school teachers, hunters, shortorder cooks, college students, vegans, and more. Visit Mark Menjivar’s portrait exhibition, “You Are What You Eat” (Note 1.7 "Interactive 1.1"). Menjivar hopes these images will invoke new thoughts about, “How we care for our bodies. How we care for others. And how we care for the land.” As you look at these images think about your personal health, the health of your family and friends, and the health of this planet. These hopes encompass the inspirations for this book. 1.1 Defining Nutrition, Health, and Disease 13 Chapter 1 Nutrition and You Interactive 1.1 Mark Menjivar has traveled around the United States taking photographs of the contents of refrigerators of numerous types of people. The portraits are available for viewing on his website under “You Are What You Eat.” http://markmenjivar.com/you-are-what-you-eat/statement/ Nutrition and Health and Disease In 1946, the World Health Organization (WHO) defined health3 as “a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity.”World Health Organization. Preamble to the Constitution of the World Health Organization as adopted by the International Health Conference, New York, June 19–July 22, 1946. http://www.who.int/suggestions/faq/en/ This definition was adopted into the WHO consititution in 1948 and has not been ammended since. A triangle is often used to depict the equal influences of physical, mental, and social well-being on health. Disease4 is defined as any abnormal condition affecting the health of an organism, and is characterized by specific signs and symptoms. Signs refer to identifying characteristics of a disease such as swelling, weight loss, or fever. Symptoms are the features of a disease recognized by a patient and/or their doctor. Symptoms can include nausea, fatigue, irritability, and pain. Diseases are broadly categorized as resulting from pathogens (i.e., bacteria, viruses, fungi, and parasites), deficiencies, genetics, and physiological dysfunction. Diseases that primarily affect physical health are those that impair body structure (as is the case with osteoporosis), or functioning (as is the case with cardiovascular disease). Mental illnesses primarily affect mental and social wellbeing. 3. A state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity. 4. Any abnormal condition that affects the health of an organism and is characterized by specific signs and symptoms. 1.1 Defining Nutrition, Health, and Disease 14 Chapter 1 Nutrition and You The foods we eat affect all three aspects of our health. For example, a teen with Type 2 diabetes (a disease brought on by poor diet) is first diagnosed by physical signs and symptoms such as increased urination, thirstiness, and unexplained weight loss. But research has also found that teens with Type 2 diabetes have impaired thinking and do not interact well with others in school, thereby affecting mental and social wellbeing. Type 2 diabetes is just one example of a physiological disease that affects all aspects of health—physical, mental, and social. Public Health and Disease Prevention In 1894, the first congressional funds were appropriated to the US Department of Agriculture (USDA) for the study of the relationship between nutrition and human health. Dr. Wilbur Olin Atwater was appointed as the Chief of Nutrition Investigations and is accoladed as the “Father of Nutrition Science” in America.Combs, G.F. “Celebration of the Past: Nutrition at USDA.” J Nutr 124, no. 9 supplement (1994): 1728S–32S. http://jn.nutrition.org/content/124/9_Suppl/ 1728S.long Under his guidance the USDA released the first bulletin to the American public that contained information on the amounts of fat, carbohydrates, proteins, and food energy in various foods. Nutritional science advanced considerably in these early years, but it took until 1980 for the USDA and the US Department of Health and Human Services (HHS) to jointly release the first edition of Nutrition and Your Health: Dietary Guidelines for Americans. Although wide distribution of dietary guidelines did not come about until the 1980s, many historical events that demonstrated the importance of diet to health preceded their release. Assessments of the American diet in the 1930s led President Franklin D. Roosevelt to declare in his inaugural address on January 20, 1937, “I see one-third of our nation is ill-housed, ill-clad, and ill-nourished.” From the time of Atwater until the onset of the Great Depression nutritional scientists had discovered many of the vitamins and minerals essential for the functioning of the human body. Their work and the acknowledgement by President FDR of the nutritional inadequacy of the American diet evoked a united response between scientists and government leading to the enrichment of flour, the development of school lunch programs, and advancements of nutritional education in this country. 1.1 Defining Nutrition, Health, and Disease 15 Chapter 1 Nutrition and You Figure 1.2 The Federal Government’s New and Improved Tool of Nutritional Communication In the latter part of the twentieth century nutritional scientists, public health organizations, and the American public increasingly recognized that eating too much of certain foods is linked to chronic diseases. We now know that diet-related conditions and diseases include hypertension (high blood pressure), obesity, Type 2 diabetes, cardiovascular disease, some cancers, and osteoporosis. These diet-related conditions and diseases are some of the biggest killers of Americans. The HHS reports that unhealthy diets and inactivity cause between 310,000 and 580,000 deaths every single year.Center for Science in the Public Interest. “Nutrition Policy.” Accessed March 1, 2012. http://www.cspinet.org/nutritionpolicy/ nutrition_policy.html#disease According to the USDA, eating healthier could save Americans over $70 billion per year and this does not include the cost of obesity, which is estimated to cost a further $117 billion per year.Combs, G.F. “Celebration of the Past: Nutrition at USDA.” J Nutr 124, no. 9 supplement (1994): 1728S–32S. http://jn.nutrition.org/content/124/9_Suppl/1728S.long Unfortunately, despite the fact that the prevalence of these diseases can be decreased by healthier diets and increased physical activity, the CDC reports that the federal government spends one thousand times more to treat disease than to prevent it ($1,390 versus $1.21 per person each year).Combs, G.F. “Celebration of the Past: Nutrition at USDA.” J Nutr 124, no. 9 supplement (1994): 1728S–32S. http://jn.nutrition.org/content/124/ 9_Suppl/1728S.long In 2010, the new edition of the dietary guidelines identified 1.1 Defining Nutrition, Health, and Disease 16 Chapter 1 Nutrition and You obesity as the number one nutritional-related health problem in the United States and established strategies to combat its incidence and health consequences in the American population. A 2008 study in the journal Obesity reported that if current trends are not changed, 100 percent of Americans will be overweight or obese in 2048!Wang Y, et al. “Will All Americans Become Overweight or Obese? Estimating the Progression and Cost of the US Obesity Epidemic.” Obesity 10, no. 16 (October 2008): 2323–30. http://www.nature.com/oby/journal/v16/n10/full/ oby2008351a.html In 2011, the US federal government released a new multimedia tool that aims to help Americans choose healthier foods from the five food groups (grains, vegetables, fruits, dairy, and proteins). The tool, called “Choose MyPlate,” is available at choosemyplate.gov. KEY TAKEAWAYS • Health is defined as “a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity.”World Health Organization. “WHO definition of health.” http://www.who.int/ about/definition/en/print.html. • Disease is defined as any abnormal condition that affects the health of an organism, and is characterized by specific signs and symptoms. • Disease affects all three aspects of the health triangle. • Good nutrition provides a mechanism to promote health and prevent disease. • Diet-related conditions and diseases include obesity, Type 2 diabetes, cardiovascular disease, some cancers, and osteoporosis. • It took until the 1980s for the US federal government to develop a dietrelated public policy designed to equip Americans with the tools to change to a healthier diet. DISCUSSION STARTERS 1. How might the way we nourish our bodies affect planetary health? 2. Debate your classmates: Should the federal government be concerned with what Americans eat? 1.1 Defining Nutrition, Health, and Disease 17 Chapter 1 Nutrition and You 1.2 What Are Nutrients? LEARNING OBJECTIVES 1. Define the word “nutrient” and identify the six classes of nutrients essential for health. 2. List the three energy-yielding nutrients and their energy contribution. What’s in Food? h 5. Substances required by the body that must be obtained from the diet. du c o t e m e r e g Ima d e v o rig y p o r st e r t s n o i t ic The foods we eat contain nutrients5. Nutrients are substances required by the body to perform its basic functions. Nutrients must be obtained from diet, since the human body does not synthesize them. Nutrients are used to produce energy, detect and respond to environmental surroundings, move, excrete wastes, respire 18 Chapter 1 Nutrition and You (breathe), grow, and reproduce. There are six classes of nutrients required for the body to function and maintain overall health. These are carbohydrates, lipids, proteins, water, vitamins, and minerals. Foods also contain nonnutrients that may be harmful (such as cholesterol, dyes, and preservatives) or beneficial (such as antioxidants). Nonnutrient substances in food will be further explored in Chapter 8 "Nutrients Important As Antioxidants". Macronutrients Nutrients that are needed in large amounts are called macronutrients6. There are three classes of macronutrients: carbohydrates, lipids, and proteins. These can be metabolically processed into cellular energy. The energy from macronutrients comes from their chemical bonds. This chemical energy is converted into cellular energy that is then utilized to perform work, allowing our bodies to conduct their basic functions. A unit of measurement of food energy is the calorie. On nutrition food labels the amount given for “calories” is actually equivalent to each calorie multiplied by one thousand. A kilocalorie (one thousand calories, denoted with a small “c”) is synonymous with the “Calorie” (with a capital “C”) on nutrition food labels. Water is also a macronutrient in the sense that you require a large amount of it, but unlike the other macronutrients it does not yield calories. Carbohydrates Carbohydrates7 are molecules composed of carbon, hydrogen, and oxygen. The major food sources of carbohydrates are grains, milk, fruits, and starchy vegetables like potatoes. Nonstarchy vegetables also contain carbohydrates, but in lesser quantities. Carbohydrates are broadly classified into two forms based on their chemical structure: fast-releasing carbohydrates, often called simple sugars, and slow-releasing carbohydrates. Fast-releasing carbohydrates consist of one or two basic units. Examples of simple sugars include sucrose, the type of sugar you would have in a bowl on the breakfast table, and glucose, the type of sugar that circulates in your blood. 6. Nutrients that are needed in large amounts. Includes carbohydrates, lipids, proteins, and water. 7. Organic molecules composed of carbon, hydrogen, and oxygen. There are two basic forms: simple sugars and complex sugars. 1.2 What Are Nutrients? 19 Chapter 1 Nutrition and You h du c o t e m e r e g Ima d e v o rig y p o r st e r t s n o i t ic Slow-releasing carbohydrates are long chains of simple sugars that can be branched or unbranched. During digestion, the body breaks down all slow-releasing carbohydrates to simple sugars, mostly glucose. Glucose is then transported to all our cells where it is stored, used to make energy, or used to build macromolecules. Fiber is also a slow-releasing carbohydrate, but it cannot be broken down in the human body and passes through the digestive tract undigested unless the bacteria that inhabit the gut break it down. One gram of carbohydrates yields four kilocalories of energy for the cells in the body to perform work. In addition to providing energy and serving as building blocks for bigger macromolecules, carbohydrates are essential for proper functioning of the nervous system, heart, and kidneys. As mentioned, glucose can be stored in the body for future use. In humans, the storage molecule of carbohydrates is called glycogen and in plants it is known as starches. Glycogen and starches are slow-releasing carbohydrates. Lipids 8. A family of organic compounds composed of carbon, hydrogen, and oxygen. They are insoluble in water. The three main types of lipids are triglycerides, phospholipids, and sterols. 1.2 What Are Nutrients? Lipids8 are also a family of molecules composed of carbon, hydrogen, and oxygen, but unlike carbohydrates, they are insoluble in water. Lipids are found predominately in butter, oils, meats, dairy products, nuts, and seeds, and in many processed foods. The three main types of lipids are triglycerides (triacylglycerols), 20 Chapter 1 Nutrition and You phospholipids, and sterols. The main job of lipids is to store energy. Lipids provide more energy per gram than carbohydrates (nine kilocalories per gram of lipids versus four kilocalories per gram of carbohydrates). In addition to energy storage, lipids serve as cell membranes, surround and protect organs, aid in temperature regulation, and regulate many other functions in the body. Proteins Proteins9 are macromolecules composed of chains of subunits called amino acids. Amino acids are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. The food sources of proteins are meats, dairy products, seafood, and a variety of different plant-based foods, most notably soy. The word protein comes from a Greek word meaning “of primary importance,” which is an apt description of these macronutrients; they are also known colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram; however providing energy is not protein’s most important function. Proteins provide structure to bones, muscles and skin, and play a role in conducting most of the chemical reactions that take place in the body. Scientists estimate that greater than one-hundred thousand different proteins exist within the human body. Water There is one other nutrient that we must have in large quantities: water. Water does not contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More than 60 percent of your total body weight is water. Without it, nothing could be transported in or out of the body, chemical reactions would not occur, organs would not be cushioned, and body temperature would fluctuate widely. On average, an adult consumes just over two liters of water per day from food and drink. According to the “rule of threes,” a generalization supported by survival experts, a person can survive three minutes without oxygen, three days without water, and three weeks without food. Since water is so critical for life’s basic processes, the amount of water input and output is supremely important, a topic we will explore in detail in Chapter 7 "Nutrients Important to Fluid and Electrolyte Balance". 9. Macromolecules composed of chains of organic monomeric subunits, called amino acids. Amino acids are simple monomers composed of carbon, oxygen, hydrogen, and nitrogen. 10. Nutrients needed in smaller amounts. Includes vitamins and minerals. 1.2 What Are Nutrients? Micronutrients Micronutrients10 are nutrients required by the body in lesser amounts, but are still essential for carrying out bodily functions. Micronutrients include all the essential minerals and vitamins. There are sixteen essential minerals and thirteen vitamins (See Table 1.1 "Minerals and Their Major Functions" and Table 1.2 "Vitamins and Their Major Functions" for a complete list and their major functions). In contrast to carbohydrates, lipids, and proteins, micronutrients are not directly used for making 21 Chapter 1 Nutrition and You energy, but they assist in the process as being part of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical reactions in the body and are involved in all aspects of body functions from producing energy, to digesting nutrients, to building macromolecules. Micronutrients play many roles in the body. Minerals Minerals are solid inorganic substances that form crystals and are classified depending on how much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine, are only required in a few milligrams or less and macrominerals, such as calcium, magnesium, potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are critical for enzyme function, others are used to maintain fluid balance, build bone tissue, synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against harmful free radicals. Table 1.1 Minerals and Their Major Functions Minerals Major Functions Macro Sodium Fluid balance, nerve transmission, muscle contraction Chloride Fluid balance, stomach acid production Potassium Fluid balance, nerve transmission, muscle contraction Calcium Bone and teeth health maintenance, nerve transmission, muscle contraction, blood clotting Phosphorus Bone and teeth health maintenance, acid-base balance Magnesium Protein production, nerve transmission, muscle contraction Sulfur Protein production Trace 1.2 What Are Nutrients? Iron Carries oxygen, assists in energy production Zinc Protein and DNA production, wound healing, growth, immune system function Iodine Thyroid hormone production, growth, metabolism Selenium Antioxidant Copper Coenzyme, iron metabolism Manganese Coenzyme 22 Chapter 1 Nutrition and You Minerals Major Functions Fluoride Bone and teeth health maintenance, tooth decay prevention Chromium Assists insulin in glucose metabolism Molybdenum Coenzyme Vitamins The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin, pantothenic acid, pyroxidine, biotin, folate and cobalamin. The fat-soluble vitamins are A, D, E, and K. Vitamins are required to perform many functions in the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal vision, nervous system function, and immune system function. Vitamin deficiencies can cause severe health problems. For example, a deficiency in niacin causes a disease called pellagra, which was common in the early twentieth century in some parts of America. The common signs and symptoms of pellagra are known as the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better diets relieved the signs and symptoms of pellagra, many people with the disease ended up in insane asylums awaiting death. Other vitamins were also found to prevent certain disorders and diseases such as scurvy (vitamin C), night blindness (vitamin A), and rickets (vitamin D). Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions Water-soluble B1 (thiamine) 1.2 What Are Nutrients? Coenzyme, energy metabolism assistance 23 Chapter 1 Nutrition and You Vitamins Major Functions B2 (riboflavin) Coenzyme, energy metabolism assistance B3 (niacin) Coenzyme, energy metabolism assistance B5 (pantothenic acid) Coenzyme, energy metabolism assistance B6 (pyroxidine) Coenzyme, amino acid synthesis assistance Biotin Coenzyme Folate Coenzyme, essential for growth B12 (cobalamin) Coenzyme, red blood cell synthesis C Collagen synthesis, antioxidant Fat-soluble A Vision, reproduction, immune system function D Bone and teeth health maintenance, immune system function E Antioxidant, cell membrane protection K Bone and teeth health maintenance, blood clotting Food Quality One measurement of food quality is the amount of nutrients it contains relative to the amount of energy it provides. High-quality foods are nutrient dense, meaning they contain lots of the nutrients relative to the amount of calories they provide. Nutrient-dense foods are the opposite of “empty-calorie” foods such as carbonated sugary soft drinks, which provide many calories and very little, if any, other nutrients. Food quality is additionally associated with its taste, texture, appearance, microbial content, and how much consumers like it. Food: A Better Source of Nutrients It is better to get all your micronutrients from the foods you eat as opposed to from supplements. Supplements contain only what is listed on the label, but foods contain many more macronutrients, micronutrients, and other chemicals, like antioxidants that benefit health. While vitamins, multivitamins, and supplements are a $20 billion industry in this country and more than 50 percent of Americans purchase and use them daily, there is no consistent evidence that they are better than food in promoting health and preventing disease. Dr. Marian Neuhouser, associate of the Fred Hutchinson Cancer Research Center in Seattle, says that “…scientific data are lacking on the long-term health benefits of supplements. To our surprise, we found that multivitamins did not lower the risk of the most 1.2 What Are Nutrients? 24 Chapter 1 Nutrition and You common cancers and also had no impact on heart disease.”Woodward, K. “Multivitamins Each Day Will Not Keep Common Cancers Away; Largest Study of Its Kind Provides Definitive Evidence that Multivitamins Will Not Reduce Risk of Cancer or Heart Disease in Postmenopausal Women.” Fred Hutchinson Cancer Research Center. Center News 16 (February 2009). http://www.fhcrc.org/about/ pubs/center_news/online/2009/02/multivitamin_study.html KEY TAKEAWAYS • Foods contain nutrients that are essential for our bodies to function. • Four of the classes of nutrients required for bodily function are needed in large amounts. They are carbohydrates, lipids, proteins, and water, and are referred to as macronutrients. • Two of the classes of nutrients are needed in lesser amounts, but are still essential for bodily function. They are vitamins and minerals. • One measurement of food quality is the amount of essential nutrients a food contains relative to the amount of energy it has (nutrient density). DISCUSSION STARTERS 1. Make a list of some of your favorite foods and visit the “What’s In the Foods You Eat?” search tool provided by the USDA. What are some of the nutrients found in your favorite foods? http://www.ars.usda.gov/Services/docs.htm?docid=17032 1.2 What Are Nutrients? 25 Chapter 1 Nutrition and You 1.3 The Broad Role of Nutritional Science LEARNING OBJECTIVE 1. Provide an example of how the scientific method works to promote health and prevent disease. How to Determine the Health Effects of Food and Nutrients Similar to the method by which a police detective finally charges a criminal with a crime, nutritional scientists discover the health effects of food and its nutrients by first making an observation. Once observations are made, they come up with a hypothesis, test their hypothesis, and then interpret the results. After this, they gather additional evidence from multiple sources and finally come up with a conclusion on whether the food suspect fits the claim. This organized process of inquiry used in forensic science, nutritional science, and every other science is called the scientific method11. Below is an illustration of the scientific method at work—in this case to prove that iodine is a nutrient.Zimmerman, M.B. “Research on Iodine Deficiency and Goiter in the 19th and Early 20th Centuries.” J Nutr 138, no. 11 (November 2008): 2060–63. http://jn.nutrition.org/content/138/11/2060.full, Carpenter, K.J. “David Marine and the Problem of Goiter.” J Nutr 135, no.4 (April 2005): 675–80. http://jn.nutrition.org/content/135/4/675.full?sid=d06fdd35-566f -42a2-a3fdefbe0736b7ba In 1811, French chemist Bernard Courtois was isolating saltpeter for producing gunpowder to be used by Napoleon’s army. To carry out this isolation he burned some seaweed and in the process observed an intense violet vapor that crystallized when he exposed it to a cold surface. He sent the violet crystals to an expert on gases, Joseph Gay-Lussac, who identified the crystal as a new element. It was named iodine, the Greek word for violet. The following scientific record is some of what took place in order to conclude that iodine is a nutrient. 11. The process of inquiry that involves making an observation, coming up with a hypothesis, conducting a test of that hypothesis, evaluating results, gathering more supporting evidence, and coming up with a conclusion. Observation. Eating seaweed is a cure for goiter, a gross enlargement of the thyroid gland in the neck. Hypothesis. In 1813, Swiss physician Jean-Francois Coindet hypothesized that the seaweed contained iodine and he could use just iodine instead of seaweed to treat his patients. 26 Chapter 1 Nutrition and You Experimental test. Coindet administered iodine tincture orally to his patients with goiter. Interpret results. Coindet’s iodine treatment was successful. Gathering more evidence. Many other physicians contributed to the research on iodine deficiency and goiter. Hypothesis. French chemist Chatin proposed that the low iodine content in food and water of certain areas far away from the ocean were the primary cause of goiter and renounced the theory that goiter was the result of poor hygiene. Experimental test. In the late 1860s the program, “The stamping-out of goiter,” started with people in several villages in France being given iodine tablets. Results. The program was effective and 80 percent of goitrous children were cured. Hypothesis. In 1918, Swiss doctor Bayard proposed iodizing salt as a good way to treat areas endemic with goiter. Experimental test. Iodized salt was transported by mules to a small village at the base of the Matterhorn where more than 75 percent of school children were goitrous. It was given to families to use for six months. Results. The iodized salt was beneficial in treating goiter in this remote population. Experimental test. Physician David Marine conducted the first experiment of treating goiter with iodized salt in America in Akron, Ohio. Results. This study conducted on over four-thousand school children found that iodized salt prevented goiter. Conclusions. Seven other studies similar to Marine’s were conducted in Italy and Switzerland that also demonstrated the effectiveness of iodized salt in treating goiter. In 1924, US public health officials initiated the program of iodizing salt and started eliminating the scourge of goiterism. Today more than 70 percent of American households use iodized salt and many other countries have followed the same public health strategy to reduce the health consequences of iodine deficiency. 1.3 The Broad Role of Nutritional Science 27 Chapter 1 Nutrition and You Evidence-Based Approach to Nutrition It took more than one hundred years from iodine’s discovery as an effective treatment for goiter until public health programs recognized it as such. Although a lengthy process, the scientific method is a productive way to define essential nutrients and determine their ability to promote health and prevent disease. The scientific method is part of the overall evidence-based approach to designing nutritional guidelines. An evidence-based approach to nutrition includes:Briss, P.A., et al. “Developing an Evidence-Based Guide to Community Preventive Services—Methods.” Am J Prev Med 18, no. 1S (2000): 35–43., Myers, E. “Systems for Evaluating Nutrition Research for Nutrition Care Guidelines: Do They Apply to Population Dietary Guidelines?” J Am Diet Assoc 103, no. 12, supplement 2 (December 2003): 34–41. • Defining the problem or uncertainty (e.g., the rate of colon cancer is higher in people who eat red meat) • Formulating it as a question (e.g., Does eating red meat contribute to colon cancer?) • Setting criteria for quality evidence • Evaluating the body of evidence • Summarizing the body of evidence and making decisions • Specifying the strength of the supporting evidence required to make decisions • Disseminating the findings The Food and Nutrition Board of the Institute of Medicine, a nonprofit, nongovernmental organization, constructs its nutrient recommendations (i.e., Dietary Reference Intakes, or DRI) using an evidence-based approach to nutrition. The entire procedure for setting the DRI is documented and made available to the public. The same approach is used by the USDA and HHS, which are departments of the US federal government. The USDA and HHS websites are great tools for discovering ways to optimize health; however, it is important to gather nutrition information from multiple resources as there are often differences in opinion among various scientists and public health organizations. While the new Dietary Guidelines, published in 2010, have been well-received by some, there are nongovernmental public health organizations that are convinced that some pieces of the guidelines may be influenced by lobbying groups and/or the food industry. For example, the Harvard School of Public Health (HSPH) feels the government falls short by being “too lax on refined grains.”The Harvard School of Public Health. “New US Dietary Guidelines: Progress, Not Perfection.” © 2012 The President and Fellows of Harvard College. http://www.hsph.harvard.edu/nutritionsource/whatshould-you-eat/dietary-guidelines -2010/index.html The guidelines recommend 1.3 The Broad Role of Nutritional Science 28 Chapter 1 Nutrition and You getting at least half of grains from whole grains—according to the HSPH this still leaves too much consumption of refined grains. For a list of reliable sources that advocate good nutrition to promote health and prevent disease using evidence-based science see Table 1.3 "Web Resources for Nutrition and Health". In Chapter 2 "Achieving a Healthy Diet", we will further discuss distinguishing criteria that will enable you to wade through misleading nutrition information and instead gather your information from reputable, credible websites and organizations. Table 1.3 Web Resources for Nutrition and Health Organization Website Governmental US Department of Agriculture http://www.usda.gov/wps/portal/usda/ usdahome USDA Center for Nutrition Policy and Promotion http://www.cnpp.usda.gov/ US Department of Health and Human Services http://www.hhs.gov/ Centers for Disease Control and Prevention http://www.cdc.gov/ Food and Drug Administration http://www.fda.gov/ Healthy People http://www.healthypeople.gov/2020/ default.aspx Office of Disease Prevention and Health Promotion http://odphp.osophs.dhhs.gov/ Health Canada http://www.hc-sc.gc.ca/ International World Health Organization http://www.who.int/en/ Food and Agricultural Organization of the United Nations http://www.fao.org/ Nongovernmental Harvard School of Public Health http://www.hsph.harvard.edu/ nutritionsource/index.html Mayo Clinic http://www.mayoclinic.com/ Linus Pauling Institute http://lpi.oregonstate.edu/ 1.3 The Broad Role of Nutritional Science 29 Chapter 1 Nutrition and You Organization Website American Society for Nutrition http://www.nutrition.org/ American Medical Association http://www.ama-assn.org/ American Diabetes Association http://www.diabetes.org/ The Academy of Nutrition and Dietetics http://www.eatright.org/ Institute of Medicine: Food and Nutrition http://www.iom.edu/Global/Topics/FoodNutrition.aspx Dietitians of Canada http://www.dietitians.ca/ Types of Scientific Studies There are many types of scientific studies that can be used to provide supporting evidence for a particular hypothesis. The various types of studies include epidemiological studies, interventional clinical trials, and randomized clinical interventional trials. 12. Scientific investigations that define frequency, distribution, and patterns of health events in a population. Epidemiological studies12 are observational studies and are often the front-line studies for public health. The CDC defines epidemiological studies as scientific investigations that define frequency, distribution, and patterns of health events in a population. Thus, these studies describe the occurrence and patterns of health events over time. The goal of an epidemiological study is to find factors associated with an increased risk for a health event, though these sometimes remain elusive. An example of an epidemiological study is the Framingham Heart Study, a project of the National Heart, Lung and Blood Institute and Boston University that has been ongoing since 1948. This study first examined the physical health and lifestyles of 5,209 men and women from the city of Framingham, Massachusetts and has now incorporated data from the children and grandchildren of the original participants. One of the seminal findings of this ambitious study was that higher cholesterol levels in the blood are a risk factor for heart disease.The Framingham Heart Study, a project of the National Heart, Lung, and Blood Institute and Boston University. “History of the Framingham Heart Study.” © 2012 Framingham Heart Study. http://www.framinghamheartstudy.org/about/history.html Epidemiological studies are a cornerstone for examining and evaluating public health and some of their advantages are that they can lead to the discovery of disease patterns and risk factors for diseases, and they can be used to predict future healthcare needs and provide information for the design of disease prevention strategies for entire populations. Some shortcomings of epidemiological studies are that investigators cannot control environments and lifestyles, a specific group of people studied may not be an accurate depiction of an entire population, and these types of scientific studies cannot directly determine if one variable causes another. 1.3 The Broad Role of Nutritional Science 30 Chapter 1 Nutrition and You Interventional clinical trial studies13 are scientific investigations in which a variable is changed between groups of people. When well done, this type of study allows one to determine causal relationships. An example of an interventional clinical trial study is the Dietary Approaches to Stop Hypertension (DASH) trial published in the April 1997 issue of The New England Journal of Medicine.Appel, L. J., et al. “A Clinical Trial of the Effects of Dietary Patterns on Blood Pressure.,” N Engl J Med 336 (April 1997): 1117–24. http://www.nejm.org/doi/full/10.1056/ NEJM199704173361601 In this study, 459 people were randomly assigned to three different groups; one was put on an average American control diet, a second was put on a diet rich in fruits and vegetables, and the third was put on a combination diet rich in fruits, vegetables, and low-fat dairy products with reduced saturated and total fat intake. The groups remained on the diets for eight weeks. Blood pressures were measured before starting the diets and after eight weeks. Results of the study showed that the group on the combination diet had significantly lower blood pressure at the end of eight weeks than those who consumed the control diet. The authors concluded that the combination diet is an effective nutritional approach to treat high blood pressure. The attributes of high-quality clinical interventional trial studies are: • those that include a control group, which does not receive the intervention, to which you can compare the people who receive the intervention being tested; • those in which the subjects are randomized into the group or intervention group, meaning a given subject has an equal chance of ending up in either the control group or the intervention group. This is done to ensure that any possible confounding variables are likely to be evenly distributed between the control and the intervention groups; • those studies that include a sufficient number of participants. What are confounding variables? These are factors other than the one being tested that could influence the results of the study. For instance, in the study we just considered, if one group of adults did less physical activity than the other, then it could be the amount of physical activity rather than the diet being tested that caused the differences in blood pressures among the groups. 13. Scientific investigations in which a variable is changed between groups of people. The limitations of these types of scientific studies are that they are difficult to carry on for long periods of time, are costly, and require that participants remain compliant with the intervention. Furthermore, it is unethical to study certain interventions. (An example of an unethical intervention would be to advise one group of pregnant mothers to drink alcohol to determine the effects of alcohol intake on pregnancy outcome, because we know that alcohol consumption during pregnancy damages the developing fetus.) 1.3 The Broad Role of Nutritional Science 31 Chapter 1 Nutrition and You Randomized clinical interventional trial studies 14 are powerful tools to provide supporting evidence for a particular relationship and are considered the “gold standard” of scientific studies. A randomized clinical interventional trial is a study in which participants are assigned by chance to separate groups that compare different treatments. Neither the researchers nor the participants can choose which group a participant is assigned. However, from their limitations it is clear that epidemiological studies complement interventional clinical trial studies and both are necessary to construct strong foundations of scientific evidence for health promotion and disease prevention. Other scientific studies used to provide supporting evidence for a hypothesis include laboratory studies conducted on animals or cells. An advantage of this type of study is that they typically do not cost as much as human studies and they require less time to conduct. Other advantages are that researchers have more control over the environment and the amount of confounding variables can be significantly reduced. Moreover, animal and cell studies provide a way to study relationships at the molecular level and are also helpful in determining the exact mechanism by which a specific nutrient causes a change in health. The disadvantage of these types of studies are that researchers are not working with whole humans and thus the results may not be relevant. Nevertheless, wellconducted animal and cell studies that can be repeated by multiple researchers and obtain the same conclusion are definitely helpful in building the evidence to support a scientific hypothesis. Evolving Science Science is always moving forward, albeit sometimes slowly. One study is not enough to make a guideline or a recommendation or cure a disease. Science is a stepwise process that builds on past evidence and finally culminates into a well-accepted conclusion. Unfortunately, not all scientific conclusions are developed in the interest of human health and it is important to know where a scientific study was conducted and who provided the money. Indeed, just as an air quality study paid for by a tobacco company diminishes its value in the minds of readers, so does one on red meat performed at a laboratory funded by a national beef association. 14. Scientific investigations which incorporate a change in the variable being tested between groups of people and are therefore capable of determining a causal relationship. Science can also be contentious even amongst experts that don’t have any conflicting financial interests. Contentious science is actually a good thing as it forces researchers to be of high integrity, well-educated, well-trained, and dedicated. It also instigates public health policy makers to seek out multiple sources of evidence in order to support a new policy. Agreement involving many experts across multiple scientific disciplines is necessary for recommending dietary changes to improve health and prevent disease. Although a somewhat slow process, 1.3 The Broad Role of Nutritional Science 32 Chapter 1 Nutrition and You it is better for our health to allow the evidence to accumulate before incorporating some change in our diet. Nutritional Science Evolution One of the newest areas in the realm of nutritional science is the scientific discipline of nutritional genetics, also called nutrigenomics. Genes are part of DNA and contain the genetic information that make up all our traits. Genes are codes for proteins and when they are turned “on” or “off,” they change how the body works. While we know that health is defined as more than just the absence of disease, there are currently very few accurate genetic markers of good health. Rather, there are many more genetic markers for disease. However, science is evolving and nutritional genetics aims to identify what nutrients to eat to “turn on” healthy genes and “turn off” genes that cause disease. Eventually this field will progress so that a person’s diet can be tailored to their genetics. Thus, your DNA will determine your optimal diet. 1.3 The Broad Role of Nutritional Science 33 Chapter 1 Nutrition and You Using Science and Technology to Change the Future As science evolves, so does technology. Both can be used to create a healthy diet, optimize health, and prevent disease. Picture yourself not too far into the future: you are wearing a small “dietary watch” that painlessly samples your blood, and downloads the information to your cell phone, which has an app that evaluates the nutrient profile of your blood and then recommends a snack or dinner menu to assure you maintain adequate nutrient levels. What else is not far off? How about another app that provides a shopping list that adheres to all dietary guidelines and is emailed to the central server at your local grocer who then delivers the food to your home? The food is then stored in your smart fridge which documents your daily diet at home and delivers your weekly dietary assessment to your home computer. At your computer, you can compare your diet with other diets aimed at weight loss, optimal strength training, reduction in risk for specific diseases or any other health goals you may have. You may also delve into the field of nutritional genetics and download your gene expression profiles to a database that analyzes yours against millions of others. KEY TAKEAWAYS • The scientific method is an organized process of inquiry used in nutritional science to determine if the food suspect fits the claim. • The scientific method is part of the overall evidence-based approach to designing nutritional guidelines that are based on facts. • There are different types of scientific studies—epidemiological studies, randomized clinical interventional trial studies, and laboratory animal and cell studies—which all provide different, complementary lines of evidence. • It takes time to build scientific evidence that culminates as a commonly accepted conclusion. • Agreement of experts across multiple scientific disciplines is a necessity for recommending dietary changes to improve health and help to prevent disease. • Science is always evolving as more and more information is collected. 1.3 The Broad Role of Nutritional Science 34 Chapter 1 Nutrition and You DISCUSSION STARTERS 1. What are some of the ways in which you think like a scientist and use the scientific method in your everyday life? Any decision-making process uses at least pieces of the scientific method. Think about some of the major decisions you have made in your life and the research you conducted that supported your decision. For example, what computer brand do you own? Where is your money invested? What college do you attend? 2. Do you use technology, appliances, and/or apps that help you to optimize your health? 1.3 The Broad Role of Nutritional Science 35 Chapter 1 Nutrition and You 1.4 Health Factors and Their Impact LEARNING OBJECTIVES 1. Explain the role that genetics, environment, life cycle, and lifestyle play in health status. 2. Describe economic, social, cultural, and emotional determinants that affect personal choices of foods. In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle. These factors are referred to as “determinants” of health and they all interact with each other. For example, family income influences the food choices available and the quantity and quality of food that can be purchased, which of course affects nutrition. Except for nutrition and lifestyle, these factors can be difficult or impossible to change. Genetics Everyone starts out in life with the genes handed down to them from the families of their mother and father. Genes15 are responsible for your many traits as an individual and are defined as the sequences of DNA that code for all the proteins in your body. The expression of different genes can determine the color of your hair, skin, and eyes, and even if you are more likely to be fat or thin and if you have an increased risk for a certain disease. The sequence of DNA that makes up your genes determines your genetic makeup, also called your genome16, which is inherited from your mother and father. In 2003, the Human Genome Project was completed and now the entire sequence of DNA in humans is known. It consists of about three billion individual units and contains between twenty-five and thirty thousand genes. The human genome that was sequenced was taken from a small population of donors and is used as a reference DNA sequence for the entire population. Each of us has a similar but unique DNA sequence. Only identical twins and cloned animals have the exact same DNA sequence. 15. The sequences of DNA that code for all the proteins in your body. 16. Entire genetic information contained in an individual which is inherited from their parents. 36 Chapter 1 Nutrition and You Now that we understand the map of the human genome, let’s enter the fields of nutrigenomics and epigenetics. Recall that nutrigenomics17 is an emerging scientific discipline aimed at defining healthy genes and not-sohealthy genes and how nutrients affect them. Currently, scientists cannot change a person’s DNA sequence. But they have discovered that chemical reactions in the body can turn genes “on” and “off,” causing changes in the amounts and types of proteins expressed. Epigenetics18 is another rapidly advancing scientific field in which researchers study how chemical reactions turn genes “on” and “off” and the factors that influence the chemical reactions. Some of these factors are now known to be nutrients. Researchers at the Genetic Science Learning Center at the University of Utah conducted an experiment in which some pregnant mice were fed a diet containing folate, choline, vitamin B 12, and betaine, and other pregnant mice were fed a diet that did not contain these nutrients and chemicals. Both groups of pregnant mice were also fed bisphenol A, a chemical in plastic, which alters DNA by inhibiting a specific chemical reaction. The mice born from the mother fed the supplemented diet were brown, thin, and healthy. The mice born from the mother fed the unsupplemented diet were yellow, fat, and unhealthy. This is a dramatic example of how nutrients change not the sequence of DNA, but which genes are expressed. These two mice look different, but have identical DNA sequences. Thus, not only do the things you eat determine your health, but so do the things your mother ate during pregnancy. Moreover, other studies have demonstrated what your dad ate—and what your grandmother ate while she was pregnant with your mother!—also can affect your gene expression and, consequently, your health. Does this make it OK for you to blame your mother and father for all of your shortcomings? No. Genetics are important in determining your health, but they are certainly not the only determinant. 17. An emerging scientific discipline that studies how nutrients affect gene expression. 18. A rapidly advancing scientific field, in which researchers study how non-gene factors affect gene expression. 1.4 Health Factors and Their Impact 37 Chapter 1 Nutrition and You Interactive 1.2 This is a good animation of the central foundation of modern biology. Turn “on” a gene, make messenger RNA, and make protein. Spin the dial all the way to the left to turn off the expression, and then slowly move it to the right. http://learn.genetics.utah.edu/content/epigenetics/control/ Source: Genetic Science Learning Center at the University of Utah. The Life Cycle The life cycle19 of human beings originates from a fertilized egg, which develops into a fetus that is eventually born as a baby. A baby develops into a child, transitions through the wonderful phase of adolescence, becomes an adult, and then advances into old age and eventually death. The current average life expectancy in America is approaching eighty. To see how this compares with other countries, see Note 1.39 "Interactive 1.3". 19. The stages of life one passes through until death. 1.4 Health Factors and Their Impact 38 Chapter 1 Nutrition and You Interactive 1.3 Visit this public database from the World Bank to learn how the life expectancy in America differs from those in other countries. http://www.google.com/publicdata?ds=wbwdi&met_y=sp_dyn_le00_in&idim=country:USA&dl=en&hl= en&q=america+average+life+expectancy s t es r t h g Ima o m e re c o t e u d d e v ig r y op on i t c ri A person’s stage of life influences their health and nutritional requirements. For example, when you are an adolescent, your bones grow quickly. More calcium, a bone-building nutrient, is required in the diet during this life stage than at other ages. As you get older, the aging process affects how your body functions. One effect of aging, apparently earlier in women than in men, is the deterioration of bone tissue. As a result, women over age fifty-one need more calcium in their diet than younger adult women. Another life-cycle stage, pregnancy, requires several adjustments to nutrition compared to nonpregnant women. It is recommended that 1.4 Health Factors and Their Impact 39 Chapter 1 Nutrition and You a pregnant woman consume more protein than a nonpregnant woman to support growth and development, and to consume more of some vitamins, such as folate, to prevent certain birth defects. The USDA provides information on healthy diets for many different stages of the life cycle on their website. Healthy aging requires eating a diet that matches one’s life stages to support the body’s specific physiological requirements. What else is known to help a person age slowly and gracefully? Diets high in vegetables and fruits are associated with increased longevity and a decreased risk of many diseases. Environment s t es r t h g Ima o m e re c o t e u d d e v ig r y op on i t c ri Your environment has a large influence on your health, genetics, life cycle, and lifestyle. Scientists say that the majority of your expressed traits are a product of your genes and environment, of which nutrition is a component. An example of this interaction can be observed in people who have the rare genetic disorder, phenylketonuria (PKU). The clinical signs of PKU are mental retardation, brain 1.4 Health Factors and Their Impact 40 Chapter 1 Nutrition and You damage, and seizures and are caused by the build-up of the amino acid phenylalanine and its metabolites (breakdown products produced during metabolism) in the body. The high level of phenylalanine in a person who has PKU is the result of a change in the gene that encodes for an enzyme that converts phenylalanine into the amino acid tyrosine. This genetic change, called a mutation, causes the enzyme to not function properly. In this country and many others all newborn babies are screened for PKU in order to diagnose and treat the disease before the development of mental retardation and brain damage. Once diagnosed, PKU is treated by strict adherence to a diet low in phenylalanine, consisting mostly of fruits, vegetables, and grains. Adhering to this diet for life allows an individual with PKU to lead a normal life without suffering the consequences of brain damage, mental retardation, or seizures. In the example of PKU, the consequences of a genetic mutation are modified by diet. Thus, a person’s genes can make them more susceptible to a particular disease, or cause a disease, and their environment can decrease or increase the progression and severity of the condition. Socioeconomic Status 20. A measurement dependent on three variables; income, occupation, and education. Multiple aspects of a person’s environment can affect nutrition, which in turn affects health. One of the best environmental predictors of a population’s health is socioeconomic status. Socioeconomic status20 is a measurement made up of three variables: income, occupation, and education. Socioeconomic status affects nutrition by influencing what foods you can afford and consequently, food choice and food quality. Nutrition and health are generally better in populations that have higher incomes, better jobs, and more education. On the other hand, the burden of disease is highest in the most disadvantaged populations. A commentary in the Journal of the American Medical Association reports that the lower life expectancy of populations of lower socioeconomic status is largely attributable to increased death from heart disease.Fiscella, K. and D. Tancredi. “Socioeconomic Status and Coronary Heart Disease Risk Prediction.” JAMA 300, no. 22 (2008): 2666–68. The American Heart Association states that having a healthy diet is one of the best weapons to fight heart disease and it is therefore essential that all socioeconomic status groups have access to high-quality, nutrient-dense foods. The disparities in nutrition and health in America are directly related to the disparity in socioeconomic status. Other dimensions that affect health disparity are race, ethnic group, sex, sexual identity, age, disability, and geographic location. The issue of inequitable health among Americans is recognized by the federal government and one of the overarching goals of Healthy People 2020, a large program managed by the HHS, is to “Achieve health equity, eliminate disparities, and improve the health of all groups.” To work toward this monumentous goal, the HHS is actively tracking disease patterns, chronic conditions, and death rates among the many different types of people that live in the United States. This will be further discussed in Chapter 2 "Achieving a Healthy Diet". 1.4 Health Factors and Their Impact 41 Chapter 1 Nutrition and You Interactive 1.4 To see the differences in causes of death for different sexes, races, and age groups, visit the website of Healthy People and compare the top ten causes of death for different populations. http://www.healthypeople.gov/2020/default.aspx Lifestyle One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects health. A greater discussion of this will follow in subsequent chapters in this book as there is an enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a person eats, how much a person eats during a meal, how frequently meals are consumed, and how often a person eats out at restaurants. Other aspects of lifestyle21 include physical activity level, recreational drug use, and sleeping patterns, all of which play a role in health and impact nutrition. Following a healthy lifestyle improves your overall health. In 2008, the HHS released the Physical Activity Guidelines for Americans. The HHS states that “Being physically active is one of the most important steps that Americans of all ages can take to improve their health. The 2008 Physical Activity Guidelines for Americans provides science-based guidance to help Americ...
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Running head: MEAL PLANNING FOR CARBOHYDRATES

Meal Planning for Carbohydrates
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1

MEAL PLANNING FOR CARBOHYDRATES
Meal planning for carbohydrates
Part A
1. What is meant by the AMDR, and what is this range for carbohydrates?
AMDR, short for Acceptable Macronutrient Distribution Range, is the percentage
range of each nutrient that one should consume each day. This number often varies and is
given as a range so as to allow flexibility in the diets that are consumed on a daily basis.
According to Manore (2005), the recommended range of carbohydrates fall between 45% and
65% of energy and make up the largest constitution of energy sourc...


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