101166 C P BC A Bl k P N i CMYK DESIGN SERVICES OFN

101166 C P BC A Bl k P N i C/M/Y/K DESIGN SERVICES OF
Nutrition
From Science to You
Joan Salge Blake
Boston University
Kathy D. Munoz
Humboldt State University
Stella Volpe
University of Pennsylvania
Benjamin Cummings
San Francisco Boston New York
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A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:19 AM Page i
101166 C P BC A Bl k P N ii C/M/Y/K DESIGN SERVICES OF
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Library of Congress Cataloging-in-Publication Data
Blake, Joan Salge.
Nutrition: from science to you / Joan Salge Blake, Kathy D.
Munoz, Stella Volpe.
p. cm.
Includes bibliographical references and index.
ISBN 10: 0-321-51319-3; ISBN 13: 978-0-321-51319-9
(Student edition)
ISBN 10: 0-321-59235-2; ISBN 13: 978-0-321-59235-4
(Professional copy)
1. Nutrition/—Textbooks./Munoz, Kathy D., 1951– II. Volpe,
Stella, 1963–
III. Title.

RA784.B553 2010
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iii
About the Authors
Joan Salge Blake, MS, RD, LDN

Boston University
Joan Salge Blake is a Clinical Associate Professor and Dietetics
Internship Director at
Boston University’s Sargent College of Health and
Rehabilitation Sciences. She
teaches both graduate and undergraduate nutrition courses. She
received her MS
from Boston University.
Joan is a member of the American Dietetic Association and the
Massachusetts
Dietetic Association (MDA). She has been a presenter and
Presiding Officer at both
the ADA Annual Meeting and the MDA Annual Convention and
is a guest lecturer at
the Boston University Goldman School of Dental Medicine. She
was previously
named MDA’s “Young Dietitian of the Year” and is the past
Director of Education
and Nominating Committee Chairperson for the MDA. She
currently serves on the
MDA board. Joan has received the Whitney Powers Excellence
in Teaching award
from Boston University and the Annie Galbraith Outstanding
Dietitian award from
the Massachusetts Dietetic Association.
In addition to teaching and writing, Joan has a private practice
specializing in weight
management and lifestyle changes. Joan is often asked to
translate complex nutri-
tional issues in popular terms. As an ADA National
Spokesperson she conducts over
100 media interviews annually, and is a nutrition contributor of
articles to a variety

of magazines.
Kathy D. Munoz, EdD, RD
Kathy D. Munoz is a professor of nutrition and Chair of the
Department of Kinesiol-
ogy and Recreation Administration at Humboldt State
University. She teaches under-
graduate introductory nutrition, exercise nutrition and weight
management courses,
and graduate exercise nutrition. She received her EdD from the
University of South-
ern California in curriculum design and an MS in Foods and
Nutrition with a minor
in exercise physiology from Oregon State University. Kathy has
published research in
the areas of nutrition and exercise, weight management, and
body composition.
Kathy is a member of the American Dietetic Association and the
California Dietetic
Association. She has published articles in Research Quarterly
for Exercise and Sport,
Children’s Health Care, the Journal of Nutrition Education, and
the International Jour-
nal of Sport Nutrition and Exercise, and has co-authored a
series of curriculum guides
for elementary teachers. Kathy has also been recognized for her
research in, and de-
velopment of, asynchronous learning.
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iv About the Authors
Stella L. Volpe, PhD, RD, LDN
Stella Volpe is the Miriam Stirl Term Associate Professor of
Nutrition in the School
of Nursing at University of Pennsylvania. She is a nutritionist
and exercise physiolo-
gist whose research is on obesity prevention, body composition,
bone mineral den-
sity, and mineral metabolism and exercise. Stella’s current
research revolves around
the effects of the environment on obesity. Stella teaches
introductory courses on
nutrition and on nutrition, exercise, and fitness. She received
her PhD from Virginia
Tech.
Stella is a Core Member of the Biobehavioral Research Center,
an Associated Faculty
Member of the Center for Health Disparities in the School of
Nursing, an Associate
Scholar in the Center for Clinical Epidemiology and
Biostatistics, an Associate Fac-
ulty Member in the Graduate Program in Public Health, a co-
Director in Excellence
in Partnerships for Community Outreach, Research on Health
Disparities, and
Training (EXPORT), and a Member of the Penn Diabetes
Center, all in the School of

Medicine.
Among her professional memberships, Stella is a Fellow of the
American College of
Sports Medicine and a member of the American College of
Nutrition, the American
Society for Nutritional Sciences, the American Society of
Clinical Nutrition, the
American Dietetic Association, Community-Campus
Partnerships for Health, and
Sigma Xi.
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:19 AM Page iv
We wrote Nutrition: From Science to You to provide you with a
solid foundation about
nutrition and how it affects you and your nutritional needs,
concerns, and questions.
Between the three of us, we have more than 40 years of teaching
college-level
nutrition. We’ve conducted and published research, studied the
literature, and lis-
tened to and watched our students learn this science. We’ve
made copious notes re-
garding students’ questions, interests, concerns, and
misunderstandings, both in and
outside the classroom. These years of experience have
culminated in a textbook that
we believe translates the latest nutrition science into a readable
format to provide
you with information that you can easily incorporate into your
life and the lives of
others. As a college student, you are exposed to a steady stream

of nutrition and
health information from the media, your family and friends, and
the Internet. Al-
though you may think Google has the answer to your nutrition
questions, we have
seen students frequently fall victim to misinformation found via
a quick Web search
and a few glitzy websites. We designed Nutrition: From Science
to You to be as user
friendly as possible, and packed exclusively with sound
nutrition information. The
text goes beyond basic nutrition science and provides realistic
advice and strategies
to help you apply what you learn in your own life. The text is
written to meet your
nutritional concerns and answer your questions.
As you read Nutrition: From Science to You, we want you to
feel as though you
are sitting in our class being engaged in the latest science of
nutrition. For this rea-
son, the text is written in a conversational tone designed to
visually communicate
complex nutrition science and topics in an easy-to-understand
way.
The information in each chapter is presented using a “What,”
“Why,” and
“How” format in which we explain:
“What” the nutrition concept is and the science that supports it
“Why” it is important and what role it plays in the body
“How” to easily adjust and improve your diet based on what you
just learned
“What” Is the Nutrition Concept?

Each chapter begins with a Campus Corner, a short scenario
involving a college stu-
dent who is experiencing a common nutrition-related situation
pertinent to the
chapter topic. Don’t be surprised if the student reminds you of
yourself, your room-
mate, or a relative! We want you to be able to immediately
relate to the character in
the scenario and his or her nutrition problem. As you read, you
will learn how to
apply the information in the chapter to this person’s life
situation (and yours) in a
practical way and you will see the person revisited at several
points throughout the
chapter as you learn more.
The popular Myths and Misconceptions Pretest is the chapter -
opening quiz
that will help you recognize misperceptions that you may have
about the chapter
topic. The answers to these pretest questions are woven
throughout the chapter and a
complete explanation is given at the end of the chapter.
Our vision in writing this textbook was to present the science of
nutrition and
supporting chemistry and physiology in an easy-to-understand
format surrounded
Why We Wrote
Nutrition: From Science to You
v
101166 C P BC A Bl k P N C/M/Y/K DESIGN SERVICES OF

A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:19 AM Page v
vi Preface
by colorful and visually appealing photos and illustrations that
make the informa-
tion memorable. The Visual Summary Tables have been
specifically chosen and de-
signed to help you understand and remember nutrition concepts
and the important
roles that featured nutrients play in your body and diet. You
will find these sum-
maries at the end of each macronutrient chapter (Carbohydrates,
Lipids, Proteins,
and Water). In the micronutrients chapters (Fat-Soluble
Vitamins, Water-Soluble
Vitamins, Major Minerals, and Trace Minerals), they comprise
the bulk of each
chapter. Each micronutrient is presented in a consistent, easily
studied format that
covers what the micronutrient is, its functions, daily needs, food
sources, and the
consequences of too much or too little in the diet.
The Feature boxes woven throughout the text present more in-
depth informa-
tion on up-to-date topics of interest, including protein bars,
enhanced beverages,
bottled water, and food allergies. The necessary calculations
that you will use in your
professional life are highlighted in Calculation Corner boxes,
and you’ll find a

review of key chemistry concepts in the Chemistry Boost boxes.
Because we are
passionate about our profession as Registered Dietitians (RD)
and health care pro-
fessionals, we’ve included a feature entitled Careers in
Nutrition to provide you with
an insight into this growing profession. These interviews with a
wide variety of pro-
fessionals in the field of nutrition are described briefly in the
text and can be found
in full on this book’s companion website. You’ll also note in
selected places in the text
a Health Focus icon. Whereas nutrition affects health in
innumerable ways, we have
highlighted four areas (heart disease, cancer, hypertension, and
diabetes) in which
the effects of diet are especially pronounced.
“Why” Is the Nutrition Concept
Important to You?
Chapters contain Self-Assessments that will help you determine
whether your cur-
rent diet and lifestyle habits need a little fine-tuning. The self-
assessments were de-
veloped to help you reflect upon your current diet and consider
changes to
implement. The Top Ten Points to Remember at the end of each
chapter boils down
the most important concepts of the entire chapter. Lastly, the
Putting It All Together
section at the end of each chapter builds upon all the chapters
before it and shows
you how the material learned in the current chapter fits in with
the material learned
in previous chapters.

“How” to Easily Adjust Your Lifestyle
This book is filled with tools and tips to help you make positive
diet and lifestyle
changes. The Food Source Diagrams visually provide you with
the most robust food
sources of each nutrient and are based on the MyPyramid
design. For additional in-
formation on the nutritional values of common foods, The Food
Composition Table
is available to complement this text. The Table Tips are short,
snappy lists of practi-
cal changes that will help you achieve lasting improvements in
your diet and lifestyle.
The what, why, and how of nutrition research is presented in the
Focus on Re-
search feature. These research summaries will help you develop
critical thinking
skills related to reading and interpreting current research.
Finally, the Two Points of View feature at the end of each
chapter contains ques-
tions and answers from two experts representing their
viewpoints on a timely topic.
This feature will encourage you to think critically about pro and
con arguments on a
given issue and decide for yourself which side you agree with.
You will be applying
HEALTH FOCUS
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:19 AM Page vi
the critical thinking skills that you learned in the chapter as you

read each expert’s
point of view.
Remember, nutrition matters to you! What you eat today and
tomorrow will af-
fect you and your body for years to come. Just as important,
what you learn about
nutrition today will enable you to make a positive effect on the
lives of others from
now on.
Joan Salge Blake, MS, RD, LDN
Boston University
Kathy D. Munoz, EdD, RD
Stella L. Volpe, PhD, RD, LDN
Acknowledgments
It takes a village, and then some, when it comes to writing a
dynamic textbook.
Nutrition: From Science to You is no exception. We personally
want to extend our
gratitude to all of those who passionately shared their expertise
and support to make
Nutrition: From Science to You better than we could have
envisioned.
Beginning with the energetic staff at Benjamin Cummings, we
would like to
thank Sandy Lindelof, who helped make our vision for this
textbook into a reality.
Cheryl Cechvala’s on-the-mark developmental editing improved
Nutrition: From

Science to You and made it enjoyable to read. It takes a project
manager to make sure
the village runs on a schedule, and Susan Malloy and Katie
Cook kept us on track, es-
pecially when the FedEx packages were arriving daily. A
textbook needs cracker-jack
supplements and assistant editor Emily Portwood worked
diligently to obtain the
best for Nutrition: From Science to You. Thanks also to
assistant editor Shannon Cutt
and editorial assistants Jacob Evans and Brianna Paulson for all
of their work, espe-
cially in commissioning reviewers during the developmental
stages of this book.
A very special thanks to Caroline Ayres, production supervisor
extraordinaire,
and Chris Schabow, production coordinator at The Left Coast
Group, for all of their
hard work shepherding this book through to publication. Our
humble appreciation
also goes to Kelly Murphy, art development editor, for turning
our rudimentary stick
figures into true pieces of art; to Kristin Piljay for obtaining the
most vivid and
unique photos available; to Marilyn Perry, whose design made
the text, art, and pho-
tos all came alive; and to Yvo Riezebos, whose efforts we must
thank for the book’s
beautiful cover.
Marketing takes energy, and that’s exactly what marketing
manager Neena Bali
and her energetic team seem to generate nonstop. Our
thoughtful thanks to Brooke
Suchomel for coordinating the focus groups, market research,

and enlisting the class
Preface vii
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viii Preface
OF
Reviewers
Janet Anderson
Utah State University
Sandra Baker
University of Delaware
Gita Bangera
Bellevue Community College
Lisa Blackman
Tarrant County College Northwest
Jeanne Boone
Palm Beach Community College
John Capeheart
University of Houston - Downtown
Susan Chou
American River College

Nicole Clark
Indiana University of Pennsylvania
Susan Cooper
Montana State University Great Falls
College of Technology
Jessica Coppola
Sacramento City College
Lynn Monahan Couch
West Chester University of Pennsylvania
Wendy Cunningham
California State University Sacramento
testers. The many instructors who reviewed and class-tested
early versions of this
book are listed on the following pages; we are grateful to all of
them for helping in
the development of Nutrition: From Science to You. The village
also included loyal
contributors who lent their expertise to specific chapters. They
are: Tara Smith at
East Carolina University for solidifying the nutrition and fitness
chapter; Elizabeth
Quintana at West Virginia University School of Medicine for
penning two of the
“lifecycle” chapters; and Jennifer Koslo for writing the older
adults lifecycle chapter,
as well as the hunger and food safety chapters. We also thank
Julie Lyons for her work
on the “Two Points of View” interviews.
Lastly, an endless thanks to our colleagues, friends, and

especially our families.
Joan would like to “thank my family, Adam, Brendan, and Craig
for their love and
support when I was working more than I should have been.”
Kathy sends a special
thanks to “my husband Rich and our children Heather, Wes, and
Ryan for keeping
me sane and grounded, and my Mom, Dad, and sister Vicki for
their steadfast sup-
port.” Stella would like to acknowledge “my husband, Gary
Snyder, for his constant
support; and our wonderful dogs, Asko and Cenna, for always
reminding me to stop
and smell the roses! And to my Mom and Dad, who both
instilled in me a wonderful
relationship with food, especially home grown and homemade
food.”
Susan Gaumont
Chandler-Gilbert Community
College
Jill Golden
Orange Coast College
Gloria Gonzalez
Pensacola Junior College
Donna Handley
University of Rhode Island
William Helferich
University of Illinois, Urbana
Catherine Howard
Texarkana College

Karen Israel
Anne Arundel Community College
Seema Jejurikar
Bellevue Community College
Jayanthi Kandiah
Ball State University
Vicki Kloosterhouse
Oakland Community College
Allen Knehans
University of Oklahoma
Kathy Knight
University of Mississippi
Jeannette Davidson
Bradley University
Holly Dieken
University of Texas
Johanna Donnenfield
Maricopa Community College
Roberta Durschlag
Boston University
Brenda Eissenstat
Pennsylvania State University
Sheryl L. Fuller-Espie
Cabrini College

Eugene Fenster
Monroe Community College - Longview
Alyce D. Fly
Indiana University
Sara Folta
Tufts University
Betty Forbes
West Virginia University
Sue Fredstrom
Minnesota State University
Teresa Fung
Simmons College
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:19 AM Page
viii
Shui-Ming Kuo
University at Buffalo
Robert D. Lee
Central Michigan University
Sharon Lemons
Tarrant County College Northwest
Darlene Levinson

Rose Martin
Iowa State University
Mary Martinez
Central New Mexico Community
College
George F. McNeil
Fort Hays State University
Monica Meadows
University of Texas
Kathleen Melanson
University of Rhode Island
Mithia Mukutmoni
Sierra College
Pat Munn
Longview College
Megan Murphy
Southwest Tennessee Community College
Class Testers
Janet Anderson
Utah State University
Jeanne Boone
Palm Beach Community College
Jessica Coppola
Sacramento City College
Robert Cullen

Illinois State University
Gloria Gonzales
Jill Goode-Englett
University of Northern Alabama
Debra Head
University of Central Arkansas
Lenka Humenikova-Shriver
Oklahoma State University
Allen Knehans
University of Oklahoma
Janet Levin
Darlene Levinson
Anna Miller
DeAnza College
Vijaya Narayanan
Florida International University -
University Park
Anna Page
Johnson County Community College
Nancy Parkinson
Miami University, Ohio

Renee Romig
Western Iowa Technical Community
College
Janet Sass
Northern Virginia Community
College - Annandale
Susan Swadener
California Polytechnic State University,
San Luis Obispo
Janelle Walter
Baylor University
Suzy Weems
Baylor University
Jennifer Zimmerman
Tallahassee Community College
Dan Neisner
Walla Walla Community College
Corin Nishimura
Leeward Community College
Anna Page
Johnson County Community College
Jill Patterson
Pennsylvania State University
Janet Peterson
Linfield College

Gwendolyn Pla
Howard University
Roseanne Poole
Tallahassee Community College
Linda Pope
Southwest Tennessee Community College
Elizabeth Quintana
West Virginia University
Denise Russo
Cabrillo College
Kevin Schalinske
Iowa State University
Diana Spillman
Miami University, Ohio
Sherry Stewart
Navarro College
Leeann Sticker
Northwestern State University
Susan Swadener
California Polytechnic State University,
San Luis Obispo
Janelle Walter
Baylor University
Sandy Walz
West Chester University of Pennsylvania

Daryl Wane
Pasco-Hernando College
Garrison Wilkes
University of Massachusetts at Boston
Jessie Yearwood
El Centro College
Gloria Young
Virginia State University
Maureen Zimmerman
Mesa Community College
Preface ix
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x
1 What Is Nutrition? 2
2 Tools for Healthy Eating 38
3 Digestion, Absorption, and Transport 80
4 Carbohydrates 116
5 Fats, Oils, and Other Lipids 172
6 Proteins and Amino Acids 222
7 Alcohol 268
8 Your Body’s Metabolism 300

9 Fat-Soluble Vitamins 336
10 Water-Soluble Vitamins 380
11 Water 422
12 Major Minerals 452
13 Trace Minerals 488
14 Energy Balance and Body Composition 522
15 Weight Management and Disordered Eating 548
16 Nutrition and Fitness 592
17 Life Cycle Nutrition: Pregnancy Through Infancy 632
18 Life Cycle Nutrition: Toddlers Through Adolescence 680
19 Life Cycle Nutrition: Older Adults 708
20 Food Safety and Technology 740
21 Hunger at Home and Abroad 794
A Metabolism Pathways and Biochemical Structures A-3
B Nutrition and Physical Activity Recommendations for
Canadians B-1
C The Traditional Mediterranean Diet C-1
D Calculations and Conversions D-1
E U.S. Exchange Lists for Meal Planning E-1
F Organizations and Resources F-1
Brief Contents
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:20 AM Page x
xi

1
What Is Nutrition? 2
What Drives Our Food Choices? 4
Taste and Enjoyment 4
Culture and Environment 5
Social Reasons and Trends 5
Weight Concerns, Body Image, and Health Benefits 6
Advertising 6
Time, Convenience, and Cost 6
Habits and Emotions 7
What Is Nutrition? 9
What Are Nutrients? 9
Most Nutrients Are Organic 10
Most Nutrients Are Essential 11
Some Nutrients Provide Energy 11
What Are the Primary Roles of the Individual
Nutrients? 13
Carbohydrates Are the Primary Energy Source 14
Lipids Also Provide Energy 14
Proteins Provide the Building Blocks for Tissue
Synthesis 14
Vitamins and Minerals Play Vital Roles in Metabolism 15
Water Is Critical for Numerous Functions 15
What Is Credible Nutrition Research? 16
Sound Nutrition Research Begins with the Scientific
Method 18
Research Studies and Experiments Confirm

Hypotheses 19
What Is Nutritional Genomics? 21
What Is Nutrition Assessment and What Does It
Involve? 22
Nutrition Assessment Includes Examining a Patient’s Health
and Diet History 23
Anthropometric Data Is Used to Help Assess Nutritional
Status 26
Conduct a Physical Examination 26
Collect Laboratory Data 26
How Do We Assess the Nutritional Status of a
Population Group? 27
Conduct or Review National Surveys 27
What Is Healthy People 2010? 28
How Does the American
Diet Stack Up? 29
The Quality of the
American Diet 29
Rates of Overweight
and Obesity in
Americans 30
What’s the Best Dietary
Strategy for Health? 30

The Best Way to Meet Nutrient Needs Is with
a Well-Balanced Diet 30
Some Nutrient Needs Can Be Met with a
Supplement 31
2
Tools for Healthy
Eating 38
What Is Healthy Eating? 40
Healthy Eating Means Adequate Intake of Nutrients 40
Healthy Eating Involves Balance between Food
Groups 40
Healthy Eating Means Consuming a Variety of Foods 41
Healthy Eating Means Moderate Intake of All Foods 41
Healthy Eating Involves Nutrient-Dense Foods 42
Healthy Eating Involves Low-Energy-Dense Foods 43
Resources for Planning a Healthy Diet 46
What Are the Dietary Reference Intakes? 47
The DRIs Suggest an Intake Level for Each Nutrient 48
The DRIs Encompass Several Reference Values 48
The DRIs Can Be Used to Plan a Quality Diet 51
What Are the Dietary Guidelines
for Americans? 52
What Is MyPyramid? 54
MyPyramid Emphasizes Key Concepts for Planning a
Healthy Diet 54
How to Use MyPyramid 55
What Information Is on the Food Label? 62

Food Labels Are Strictly Regulated by the FDA 62
The Nutrition Facts Panel Indicates Nutrient Values 63
The Daily Values Help Compare Packaged Foods 64
Label Claims Can Reveal Potential Health Benefits 65
What Is the Exchange System? 70
Contents
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:20 AM Page xi
xii Contents
3
Digestion,
Absorption,
and Transport 80
What Are Digestion, Absorption,
and Transport? 82
What Are the Organs of the GI Tract
and Why Are They Important? 83
Digestion Begins in the Mouth 84
The Stomach Stores, Mixes, and
Prepares Food for Digestion 85
Most Digestion Occurs in the Small Intestine 86
The Large Intestine Absorbs Water and Some
Nutrients 87
The Accessory Organs Provide Digestive Juices 89

How Is Food Propelled through the GI Tract? 89
Peristalsis Squeezes Food Forward 90
Segmentation Shifts Food along the Intestinal Wall 90
How Is Food Chemically Digested? 91
Enzymes Drive the Process of Digestion 91
Other Chemicals Are Also Essential for Digestion 94
How Are Digested Nutrients Absorbed? 96
Nutrients Are Absorbed through the Small Intestinal
Lining 96
Fluid Absorption Occurs in the Large Intestine 97
How Do Hormones Affect Digestion? 98
How Does the Nervous System Affect
Digestion? 98
How Are Nutrients Transported Throughout
the Body? 99
The Circulatory System Distributes Nutrients through
Blood 99
The Lymphatic System Distributes Some Nutrients
through the Lymph 100
What Are Some Common Digestive
Disorders? 100
Esophageal Problems: Heartburn and GERD 101
Disorders of the Stomach 101
Gallbladder Disease 102
Disorders of the Intestines 102

More Serious Intestinal Disorders 105
4
Carbohydrates: Sugars,
Starches, and Fiber 116
What Are Carbohydrates and Why
Are They Important? 118
How Do We Classify Carbohydrates? 120
Monosaccharides Are Single Sugar Units 120
Disaccharides Consist of Two Sugar
Units 121
The Polysaccharides Consist of Many Sugar
Units 122
Oligosaccharides 125
How Do We Digest and Absorb
Carbohydrates? 126
Digestion of Carbohydrates 126
Absorption of Carbohydrates 128
What Is Lactose Intolerance? 129
What Functions Do Carbohydrates
Perform in the Body? 130
Carbohydrates Provide Energy and Maintain Blood Glucose
Levels 130
Carbohydrates Spare Protein 130
Carbohydrates Prevent Ketosis 131
How Do We Maintain Blood Glucose Levels? 131

Insulin Regulates Glucose in the Blood 131
Glucagon Regulates Liver Glycogenolysis 132
Epinephrine, Norepinephrine, Cortisol, and Growth
Hormone Regulate Glucose Metabolism 132
What Are Glycemic Index and Glycemic
Load? 133
Why Is Dietary Fiber So Important? 134
Fiber Helps Prevent Constipation and Diverticulosis 135
Fiber Helps Prevent Heart Disease, Diabetes, and
Cancer 135
Fiber Helps Prevent Obesity 136
What Is the Recommended Intake
for Carbohydrates? 136
What Are the Best Food Sources
of Carbohydrates? 137
Choose Whole Grains to Meet Starch and Fiber
Needs 137
Low-fat and Fat-free Dairy Products Provide Some Simple
Sugars 140
Fruits and Vegetables Provide Simple Sugars, Starch, and
Fiber 140
Legumes, Nuts, and Seeds Are Excellent Sources of Starch
and Fiber 141
Packaged Foods Can Be Good Sources of
Carbohydrates 142

What Is Diabetes? 143
There Are Several Forms of Diabetes 144
Diabetes Can Result in Long-Term Damage 145
Control Is Key 146
Preventing Type 2 Diabetes 146
Polycystic Ovary Syndrome May Increase
Risk for Diabetes 147
What Is Hypoglycemia? 147
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OF
What Is the Difference Between Natural and Added
Sugars? 149
Foods with Natural Sugars Generally Provide More
Nutrients for Fewer Kilocalories 149
Added Sugars Are Used during Food Processing 150
Finding the Added Sugars in Foods 150
Health Effects of Too Much Sugar:
Fact vs Fiction 154
Fact: Sugar Can Cause Dental Caries 154
Fiction: Sugar Causes Diabetes Mellitus 154
Fact: Too Much Sugar Can Hinder Weight Loss 154

Fiction: Sugar Is Addictive 155
Fiction: Sugar Causes Hyperactivity in Children 155
What Are Sugar Substitutes? 155
Polyols Are Sugar Alcohols 157
Saccharin Is the Oldest Sugar Substitute 157
Aspartame Is Derived from Amino Acids 159
Acesulfame-K Contains Potassium 160
Sucralose Is Made from Sucrose 160
Neotame Is Also Derived from Amino Acids 160
VISUAL SUMMARY TABLE Carbohydrates 162
5
Fats, Oils, and Other
Lipids 172
What Are Lipids and Why Are They
Important? 174
What Are Fatty Acids? 175
Fatty Acids Vary in Length 175
Fatty Acids Vary in Saturation 175
Fatty Acids Differ in the Location of the Double
Bond 177
Fatty Acids Vary in Their Shape 177
Fatty Acids and Rancidity 178
What Are Triglycerides? 179
What Are Phospholipids? 181
What Are Sterols? 183
What Happens to the Lipids You Eat? 183
Very Little Fat Digestion Occurs in the Mouth or the

Stomach 184
Most Fat Is Digested and Absorbed in the Small
Intestine 185
Chylomicrons Facilitate Lipid Absorption 186
Lipoproteins Transport Fat Through the Lymph
and Blood 187
How Does the Body Use Fat and Cholesterol? 188
Fat Is Used as Energy 189
Fat Helps Absorb Lipid Compounds 190
Fat Helps Insulate the Body and Protect Vital Organs 190
Essential Fatty Acids Manufacture Eicosanoids and
Maintain Cell Membranes 190
Cholesterol Is Used to Make Bile, Hormones, and
Vitamin D 191
How Much Fat Do We Need Each Day? 191
Percentage of Daily Kilocalories from Fat 192
Specific Recommendations for Essential Fatty Acids 193
Dietary Cholesterol Is Not Essential 196
What Are the Best Food Sources of Fat? 196
What Foods Contain Trans Fat and Cholesterol? 198
Trans Fats Are Found in Many Foods 199
Trans Fats Must Be Listed on Food Labels 199
Replacing Trans Fats in Foods 199
Food Sources of Cholesterol and Plant Sterols 200
What Are Fat Substitutes? 200
Fat Substitutes Can Be Carbohydrate, Protein, or Fat

Based 201
Consuming Reduced-Fat Products May Not Reduce Total
Kilocalorie Intake 202
What Is Heart Disease and What Factors Increase
Risk? 203
Heart Disease Begins with Atherosclerosis 203
Risk Factors for Heart Disease 204
How Can High Blood Cholesterol
Levels Be Lowered? 206
Consume Less Saturated and Trans
Fat and Moderate Cholesterol
Intake 206
Eat More Fish and Plant
Foods 208
Consume Antioxidants and
Phytochemicals 208
Get Plenty of Exercise and Manage
Your Weight 210
A Word About the Protective Effects
of Red Wine and Alcohol 211
VISUAL SUMMARY TABLE
Lipids 212
6
Proteins and Amino

Acids 222
What Are Proteins? 224
Proteins Differ Structurally from Carbohydrates and
Lipids 224
The Building Blocks of Proteins Are Amino Acids 225
The Organization and Shape of Proteins Affect Their
Function 227
Denaturation of Proteins Changes Their Shape 227
What Happens to the Protein You Eat? 229
Protein Digestion Begins in the Stomach 229
Digestion Continues in the Small Intestine 230
Amino Acids Are Absorbed in the Small Intestine 230
Amino Acids Are Metabolized in the Liver 230
xiii
xiv Contents
How Does the Body Use Protein? 234
Proteins Provide Structural Support and Enable
Movement 234
Proteins Act as Catalysts 234
Proteins Act as Chemical Messengers 234
Proteins Regulate Fluid Balance 235
Proteins Help Regulate Acid-Base Balance 235
Proteins Transport Substances Throughout the Body 235

Proteins Contribute to a Healthy Immune System 236
Proteins Can Provide Energy 236
Protein Improves Satiety and Appetite Control 237
How Much Protein Do You Need? 238
Healthy Adults Should Be in Nitrogen Balance 238
Not All Protein Is Created Equal 239
Complementary and Complete Proteins Reflect
Quality 241
You Can Determine Your Own Protein Needs 242
What Are the Best Food Sources
of Protein? 244
Eggs, Meat, Soy, and Dairy
Contain Significant Amounts
of Protein 244
You Don’t Need Protein
Supplements 245
What Happens if You Eat
Too Much or Too Little
Protein? 248
Eating Too Much Protein Can
Mean Too Much Fat and Weaker
Bones 248
Eating Too Little Protein Can Lead to Protein-Energy
Malnutrition 250
What Is a Vegetarian Diet? 251
Vegetarian Diets Carry Potential Benefits and Risks 252
Planning a Healthy Vegetarian Diet 253

VISUAL SUMMARY TABLE Protein 260
7
Alcohol 268
What Is Alcohol and How Is It Made? 270
Why Do People Drink Alcohol? 272
What Happens to Alcohol in the Body? 272
Alcohol Is Absorbed in the Stomach and Small
Intestine 274
The Liver Metabolizes Alcohol 276
Alcohol Circulates in the Blood 277
Alcohol Affects the Brain 277
What Is Moderate Drinking? 279
How Can Alcohol Be Harmful? 280
Overconsumption of Alcohol Can Have Numerous
Short-Term Consequences 280
Chronic Alcohol Abuse May Lead to Serious Health
Consequences 282
What Are Alcohol Abuse and Alcoholism? 291
Binge Drinking, Drinking and Driving, and Underage
Drinking Are Forms of Alcohol Abuse 291
Alcoholism Is a Disease 292
8
Your Body’s
Metabolism 300
What Is Metabolism? 302

Metabolism Takes Place Within Cells 303
The Liver Plays a Central Role in Metabolism 303
Metabolism Follows Individual Metabolic Pathways 304
Enzymes and Hormones Regulate Metabolism 305
How Does the Body Fuel Metabolism? 308
The Importance of Adenosine Triphosphate 308
Creating ATP from ADP and Creatine Phosphate 308
How Do Carbohydrates Provide Energy? 310
Step 1: Glycolysis—From Glucose to Pyruvate 310
Step 2: The Intermediate Reaction—Pyruvate to
Acetyl CoA 310
Pyruvate to Lactate 312
How Does Fat Provide Energy? 313
Triglycerides Are Broken Down into Fatty Acids and
Glycerol 313
The Relationship of Triglycerides to Glucose 315
How Does Protein Provide Energy? 315
Amino Acids to Acetyl CoA 315
Amino Acids to Glucose 316
Where Do the Macronutrients Come Together? 317
Step 3: The Tricarboxylic Acid (TCA) Cycle 316
The TCA Cycle Provides Precursors for
Transamination 318
Step 4: The Electron Transport Chain 318
What Happens if You Eat Too Much? 321
Carbohydrate Is Stored as Glycogen 322

Fatty Acid Synthesis 322
What Happens if You Don’t Eat Enough? 323
Ketogenesis Generates Energy during Periods of
Fasting 323
How Does the Body Metabolize Alcohol? 325
The Enzymes That Metabolize Ethanol 325
Excess Alcohol Is Stored as Fat 326
What Are Inborn Errors of Metabolism? 328
xiv
Contents xv
9
Fat-Soluble
Vitamins 336
What Are Vitamins? 338
History of Vitamins 338
The Criteria for Vitamins 339
All Vitamins Are Organic, but Differ in
Structure and Function 339
Vitamins Differ in Absorption and
Storage 340
Vitamins Differ

in Bioavailability 341
Vitamins Can Be Destroyed during
Cooking or Storage 341
Overconsumption of Some Vitamins
Can Be Toxic 342
Provitamins Can Be Converted to
Vitamins by the Body 342
What Are Antioxidants? 343
What’s the Best Source
of Vitamins? 350
What Are the Fat-Soluble
Vitamins? 354
VISUAL SUMMARY TABLE Vitamin A 356
VISUAL SUMMARY TABLE Vitamin D 362
VISUAL SUMMARY TABLE Vitamin E 368
VISUAL SUMMARY TABLE Vitamin K 370
10
Water-Soluble
Vitamins 380
What Are Water-Soluble Vitamins? 382
What Are the Primary Functions of Water-Soluble
Vitamins? 383
The B Vitamins Act as Coenzymes in Many Metabolic
Functions 384

Water-Soluble Vitamins in Noncoenzymatic Roles 384
VISUAL SUMMARY TABLE Thiamin (B1) 388
VISUAL SUMMARY TABLE Riboflavin (B2) 390
VISUAL SUMMARY TABLE Niacin (B3) 393
VISUAL SUMMARY TABLE Pantothenic Acid 396
VISUAL SUMMARY TABLE Biotin 397
VISUAL SUMMARY TABLE Vitamin B6 400
VISUAL SUMMARY TABLE Folate 402
Other Vitamin-Like Compounds 405
Choline Helps Protect the Liver 405
Carnitine, Lipoic Acid, and Inositol Are Vitamin-Like
Substances 405
VISUAL SUMMARY TABLE Vitamin B12 408
VISUAL SUMMARY TABLE Vitamin C 411
11
Water 422
Why Is Water So Important? 424
What Are the Functions of Water in the Body? 425
Water Is the Universal Solvent and Transport Medium 425
Water Helps Maintain Body Temperature 426
Water Is a Lubricant and a Protective Cushion, and
Provides Structure to Muscle Cells 426
Water Participates in Hydrolysis and Condensation
Reactions 427
How Is Water Balance Maintained? 428
Sources of Body Water Include Beverages and Food 428
Water Is Excreted through the Kidneys, Large Intestine,
Lungs, and Skin 429

Water Is Balanced between Fluid Compartments 429
Electrolytes Participate in Fluid Balance 429
How Do Water and Sodium Affect Blood
Pressure? 432
ADH Helps Stimulate Fluid Intake and Reduce Urine
Output 432
Renin Helps the Body Reabsorb Water and Salts 432
Aldosterone Helps Stimulate Sodium Reabsorption 432
How Much Water Do You Need and What Are the
Best Sources? 434
Do Diuretics Like Caffeine and Alcohol Affect
Water Balance? 438
Caffeine Does Not Cause Significant Loss of Body
Water 438
Alcohol Can Be Dehydrating 438
Diuretic Medications Can Help Treat Hypertension 438
What Are the Effects of Too Much or Too Little
Water? 439
Consuming Too Much Water Can Cause
Hyponatremia 439
Consuming Too Little Water Is a Common Problem 439
Monitor Water Intake to Avoid Overhydration and
Dehydration 442
VISUAL SUMMARY TABLE Water 444

12
Major Minerals: What Are
They and Why Do
You Need Them 452
What Are Minerals? 454
Minerals Are Inorganic Elements Needed by the Body
454
Minerals Vary in Their Bioavailability 455
Minerals Serve Numerous Functions 456
Minerals Can Be Toxic 457
VISUAL SUMMARY TABLE Sodium and Chloride 460
VISUAL SUMMARY TABLE Potassium 468
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xvi Contents
VISUAL SUMMARY TABLE Calcium 470
VISUAL SUMMARY TABLE Phosphorus 478
VISUAL SUMMARY TABLE Magnesium 480
VISUAL SUMMARY TABLE Sulfate 481
13
Trace Minerals 488
What Are Trace Minerals and Why Do
You Need Them? 490
VISUAL SUMMARY TABLE Iron 492
VISUAL SUMMARY TABLE Copper 498
VISUAL SUMMARY TABLE Zinc 500

VISUAL SUMMARY TABLE Selenium 504
VISUAL SUMMARY TABLE Fluoride? 506
VISUAL SUMMARY TABLE Chromium 508
VISUAL SUMMARY TABLE Iodine 510
VISUAL SUMMARY TABLE Molybdenum 511
VISUAL SUMMARY TABLE Manganese 512
Other Minerals: Arsenic, Boron, Nickel,
Silicon, and Vanadium 513
14
Energy Balance and
Body Composition 522
What Is Energy Balance and Why
Is It Important? 524
An Energy Imbalance Results in Weight Gain or
Loss 524
Food and Beverages Provide Energy In 525
Body Processes and Physical Activity Result in
Energy Out 526
How Do We Measure Energy Expenditure? 530
Direct and Indirect Calorimetry 530
Simple Calculations to Estimate Energy
Expenditure 530
What Is Body Composition? 532
Most Body Fat Is Stored in Adipose Tissue 532
Body Fat Distribution Affects Health 533
Body Fat Levels for Optimal Health 533
How Do We Estimate a Healthy Body Weight? 534

Height and Weight Tables Can Provide a Healthy
Weight Range 534
Body Mass Index Is a Useful Indicator of Healthy Weight for
Most People 535
How Do We Assess Body Composition? 537
Several Methods Can Be Used to Determine Percent Body
Fat 537
Waist Circumference Will Indicate Abdominal Fat 539
What Are the Health Risks Associated with Body
Weight and Body Composition? 539
Being Underweight Increases Health Risks 540
Being Overweight Increases Health Risks 540
15
Weight Management and
Disordered Eating 548
What Is the Status of Obesity in America? 550
What Is Weight Management and Why Is It
Important? 550
How Do Fat Cells Form and Expand? 552
How Is Food Intake Regulated? 554
Hunger and Satiety Affect the Desire to Eat and Stop
Eating 554
Appetite Often Triggers Eating for Unnecessary
Reasons 554

The Brain and Hormones Control Feeding 554
How Do Genetics and Environment Influence Obesity
and Weight Management? 556
Genetics Can Make the Body More Susceptible to Weight
Gain or Weight Loss 556
Environmental Factors Can Increase Appetite and Decrease
Physical Activity 557
How Can You Lose Weight Healthfully? 559
Strive for a Reasonable Rate of Weight Loss 564
Remember that Kilocalories Count 564
Eat More Vegetables, Fruit, and Fiber 565
Add Some Protein and Fat to Meals 566
Use MyPyramid as a Weight-Loss Guide 567
Increase Physical Activity to Lose Weight 568
Break Bad Habits 569
How Can Weight Loss Be Maintained? 572
What Is the Healthiest Way
to Gain Weight? 576
What Is Disordered Eating
and What Are the Warning
Signs? 577
Anorexia Nervosa Results
from Severe Kilocalorie
Restriction 579
Bulimia Nervosa Involves
Cycles of Binge Eating
and Purging 579

Binge Eating Disorder
Involves Compulsive
Overeating 580
Night Eating Syndrome Is
a Type of Eating, Sleeping,
and Mood Disorder 580
xvi
Contents xvii
There Are Some Common Signs of Disordered
Eating 581
How Are Eating Disorders Treated? 583
16
Nutrition and
Fitness 592
What Is Physical Fitness and Why Is It
Important? 594
There Are Five Basic Components of Physical
Fitness 594
Physical Fitness Provides Numerous Health
Benefits 595
What Does a Successful Physical Fitness Program

Look Like? 597
Cardiorespiratory Exercise Can Improve Cardiorespiratory
Endurance and Body Composition 597
Strength Training Can Improve Muscle Strength, Muscle
Endurance, and Body Composition 598
Stretching Can Improve Flexibility 598
The FITT Principle Can Be Used to Design a Fitness
Program 598
The Progressive Overload Principle Can Help Improve
Fitness Over Time 600
How Are Carbohydrate, Fat, and Protein Used During
Exercise? 601
Carbohydrate Is the Primary Energy Source During
High-Intensity Exercise 602
Fat Is the Primary Energy Source During Low- to Moderate-
Intensity Exercise 605
Protein Is Primarily Needed to Build and Repair
Muscle 609
Timing of Meals Affects Fitness and Athletic
Performance 610
What Vitamins and Minerals Are Important for
Fitness? 613
Antioxidants Can Help Protect Cells from Damage Caused
by Exercise 613

Some Minerals Can Be of Concern in Highly Active
People 613
Vitamin and Mineral Supplements Are Generally
Not Necessary 615
How Does Fluid Intake Affect Fitness? 615
Fluid and Electrolyte Balance and Body Temperature
Are Affected by Exercise 616
Fluids Are Needed Before, During, and After
Exercise 616
Some Beverages Are Better than Others 617
Consuming Too Little or Too Much Fluid Can Be
Harmful 618
Can Dietary Supplements Contribute
to Fitness? 620
Dietary Supplements and Ergogenic Aids May Improve
Performance, but Can Have Side Effects 621
Sports Bars and Shakes May Provide Benefits 624
17
Life Cycle Nutrition:
Pregnancy Through
Infancy 632
Why Is Good Nutrition Essential for a Healthy
Pregnancy? 634
What Are the Stages of Pregnancy and Why Is the
Placenta Important? 634

Critical Periods Impact Fetal Development 636
What Nutrients and Behaviors Are Most Important for
a Healthy Pregnancy? 638
Before Conception, Fathers-to-Be Need to Eat Well for
Healthy Sperm 638
Before Conception, Mothers Need to Adopt a Healthy
Lifestyle 638
In the First Trimester: Women Need to Eat When Food May
Not Be Appetizing, Avoid Botanicals, and Practice Food
Safety 642
In the Second Trimester:
Healthy Weight Gain and
Kilocalorie Intake Are
Important 648
In the Third Trimester: Eating
Frequent Small Meals and a
High-Fiber Diet Can Help
with Heartburn and
Constipation 651
What Special Concerns Might
Younger or Older Mothers-to-
Be Face? 651
What Is Food
Assistance? 653
What Is Breast-Feeding and
Why Is It Beneficial? 653

Breast-Feeding Provides Physical, Emotional, and Financial
Benefits for Mothers 654
Breast-Feeding Provides Nutritional and Health Benefits for
Infants 655
What Are the Nutrient Needs and Best Lifestyle
Habits for a Breast-Feeding Mother? 658
When Is Formula a Healthy Alternative to Breast
Milk? 659
Some Woman May Not Be Able to Breast-Feed 659
Formula Can Be a Healthy Alternative to
Breast-Feeding 660
What Are the Nutrient Needs of an Infant and Why Are
They So High? 661
Infants Grow at an Accelerated Rate 661
xvii
xviii Contents
OF
Infants Have Specific Kilocalorie, Iron, and Other Nutrient
Needs 662

When Are Solid Foods Safe? 664
Solid Foods May Be Introduced Once Certain Milestones
Are Met 664
Solid Foods Should Be Introduced Gradually 664
Some Foods Are Dangerous and Should Be
Avoided 665
18
Toddlers Through
Adolescence 680
What Are the Nutritional Needs and Issues for
Toddlers and Preschoolers? 682
Young Children Need to Eat Frequent, Small Meals and
Nutrient-Dense Foods 683
Young Children Need Adequate Carbohydrate, Protein,
and Fat 684
Young Children Need to Consume Enough Calcium
and Iron 685
Young Children Need to Consume Enough
Vitamin D 685
Young Children Need Nutrient-Dense Beverages 686
Picky Eating and “Food Jags” Are Common in Small
Children 686
Young Children and Vegetarianism 687
What Are the Nutritional Needs and Issues of
School-Aged Children? 688

School-Aged Children Are Experiencing Higher Rates of
Obesity 688
Increased Rates of Childhood Obesity May Lead to
Increased Rates of Type 2 Diabetes 692
School-Aged Children Should Practice Good Dental
Hygiene 693
MyPyramid For Kids Can Help Guide Food
Choices 693
What Are the Nutritional Needs and Issues of
Adolescents? 697
Adolescents Need Calcium and Iron for Growth and
Development 698
Adolescents Are Sometimes at Risk for Disordered
Eating 699
19
Older Adults 708
What Is Aging? 710
What Are the Demographics of Aging in America,
and Why Are Americans Living Longer? 711
America’s Population Is Getting Older 711
Improved Health Care
and Disease
Prevention Are
Lengthening the

Life Span 712
Smoking, Poor Diet,
and Physical Inactivity
Still Contribute to
Leading Causes of
Death 712
What Changes Occur as
Part of the Aging
Process? 713
Physiological Factors
Affect Aging 713
What Are the Nutrient Needs of Older Adults? 718
Older Adults Need Fewer Kilocalories, Not Less
Nutrition 719
Older Adults Need Adequate Protein 721
Older Adults Should Consume More Complex
Carbohydrate 721
Older Adults Should Continue to Moderate Fat
Intake 721
Older Adults Need to Watch Intake of Vitamins A, D,
and B12 721
Older Adults Need to Be Sure to Get Enough Iron, Zinc,
and Calcium 722
Older Adults Need to Stay Hydrated 723
What Additional Challenges May Older Adults
Face? 727

Eating Right for Good Health and Disease
Prevention 727
Staying Physically Active in Spite of Physical and Mental
Challenges 729
Living with Alzheimer’s Disease 729
Economic Conditions Can Affect Nutritional Health 730
Psychological and Emotional Conditions Can Affect
Nutritional Health 731
20
Food Safety and
Technology 740
What Is Food Safety and Why Is It Important? 742
What Causes Foodborne Illness? 742
Foodborne Illnesses Are Often Caused by
Pathogens 743
Some People Are at Higher Risk for Foodborne
Illness 749
What Are the Best Strategies to Prevent Foodborne
Illness? 751
Clean Hands and Produce 752
Combat Cross-Contamination 753
Cook Foods Thoroughly 753
Chill Foods at a Low Enough Temperature 754
xviii

Contents xix
What Mechanisms Are in Place to Protect the Food
Supply? 758
Several Government Agencies and Programs Protect the
Food Supply 758
Food Manufacturers Use Preservation Techniques to
Destroy Contaminants 760
Product Dating Can Help Determine Peak Quality 763
The Safety of the Water Supply Is Regulated 764
What Are Food Additives and How Are
They Used? 764
Preservatives Prevent Spoilage and Increase
Shelf Life 764
Some Additives Enhance Texture and Consistency 765
Some Additives Improve Nutrient Content 765
Color Enhancers Improve the Visual Appeal of
Foods 765
MSG Is a Common Flavor Enhancer 766
Food Additives Are Closely Regulated by the FDA 767
Some Chemicals Are Used Intentionally to Enhance the
Food Supply 767
Some Food Additives Are Unintentional 768

What Are Toxins and Chemical Agents? 769
Some Toxins Occur Naturally 769
Chemicals Are Sometimes Due to Pollution 771
Pesticides Are Widely Used in Agriculture 772
The Risks of Pesticides 773
EPA, USDA, and FDA Regulate Pesticides 773
Alternatives to Pesticides 775
Minimizing Pesticides in the Diet 776
What Are Organic Foods and How Are They
Labeled? 777
What Is Biotechnology and Why Is It Used? 780
Genetic Engineering Is the Latest Form of
Biotechnology 780
Genetic Engineering Can Produce More and Better
Foods 781
Some Consumers Have
Concerns about
GE Foods 782
GE Foods Are Highly
Regulated in the United
States 782
What Is Bioterrorism
and How Can You Protect
Yourself? 784
21
Hunger at Home and
Abroad 794
What Is Hunger and How Prevalent Is It? 796

What Causes Hunger? 799
Domestic Food Insecurity Is Caused by Poverty, Illness, or
Lack of Opportunity 799
Disease, Disability, or Illness 802
Global Hunger Is Often Caused by Inequality, Political
Conflict, Crop Failure, or Overpopulation 803
What Are the Effects of Hunger? 806
Some Populations Are at Higher Risk 806
Impaired Growth and Development 808
Impaired Immunity and Disease 809
Increased Rates of Infant and Child Mortality 810
How Can We Eradicate Hunger? 811
Biotechnology, Better Land Management, Water Usage,
and Proper Sanitation 812
Fortification of Foods Can Ensure Adequate Intake of Some
Nutrients 814
Education Is Key 814
Appendices
Appendix A
Metabolism Pathways and
Biochemical Structures A-3
Appendix B
Nutrition and Physical
Activity Recommendations
for Canadians B-1

Appendix C
The Traditional Mediterranean
Diet C-1
Appendix D
Calculations and
Conversions D-1
Appendix E
U.S. Exchange Lists for Meal
Planning E-1
Appendix F
Organizations and
Resources F-1
Glossary G-1
Index I-1
Credits CR-1
xix
xx
Feature Boxes
Evaluating Media Headlines with a Critical Eye 17
Obtaining Nutrition Advice: Who Are the Experts? Who Are
the Quacks? 24

Portion Distortion 44
Time of Day and Eating: Does It Impact Your Health? 60
Celiac Disease: An Issue of Absorption 106
Grains, Glorious Whole Grains 138
Is High-Fructose Corn Syrup Causing the Obesity
Epidemic? 152
Facts and Myths About Fats, Oils, and Cholesterol 194
Mercury and Fish 209
Protein Bars: Are They a Health Bargain? 246
The Joy of Soy 256
Alcohol and Advertising 273
Does Moderate Alcohol Consumption
Provide Health Benefits? 288
Can Energy Drinks Alter Your
Metabolism? 306
Nutrition and Cancer Prevention 346
Fortified Foods and Supplements:
Are They Necessary? 352
B Vitamins for Heart Health 385
Preventing and Treating the Common

Cold 406
Tap Water or Bottled Water: Is Bottled Better? 436
Enhanced Water: What Are We Really Drinking? 441
Controlling Hypertension 464
Building a Stronger Bone 474
Preventing Iron-Deficiency Anemia 497
Fad Diets Are the Latest Fad 560
Extreme Measures for Extreme Obesity 573
Carbohydrate Loading 606
The Truth About the Fat-Burning Zone 608
What Is the Female Athlete Triad? 622
Breast-Feeding at Work Can Work 656
A Taste Could Be Dangerous: Food Allergies 666
Does Sugar Cause ADHD? 690
Drug, Food, and Drug-Herb Interactions 716
Does Kilocalorie Restriction
Extend Life? 720
The Lowdown on Listeria 750
Mad Cow Disease 774

Farmer’s Markets 778
A Look at the Numbers: The State of
Hunger Around the World 799
Food Assistance Programs in the
United States 812
Hunger Among Us (and How You Can
Help!) 815
Boxes
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:20 AM Page xx
xxi
Self-Assessments
How Healthy Is Your Family Tree? 21
Are You at Risk for Type 2 Diabetes? 145
How Much Fat Is in Your Diet? 193
Red Flags for Alcohol Abuse 293
Are You Getting Enough Fat-Soluble Vitamins in
Your Diet? 355
Are You Getting Enough Water-Soluble Vitamins in
Your Diet? 384

Estimating Your Calcium Intake 473
Does Your Environment Impact Your Energy Balance? 557
Are You at Risk for an Eating Disorder? 582
Are You Meeting Your Fitness Recommendations and Eating
for Exercise? 625
Are You Nutritionally Ready for a Healthy Pregnancy? 642
Are You at Nutritional Risk? 731
How Do Your Food Safety Habits Stack Up? 757
Are You at Risk for Hunger? 800
Two Points of View
Food Advertisements: Help or Hindrance? 32
Does Your Diet Have Proportionality? 41
Are Supersized Portions a Super Problem for Americans? 74
Probiotics: Do They Improve Digestion? 110
Can Soft Drinks Be Part of a Healthy Diet? 165
Farmed Salmon vs Wild Salmon: Is One Healthier Than the
Other? 216
Do You Need to Eat Meat to Compete? 263
Should the Drinking Age Be Lowered? 294

Can Genetics Be Used to Improve Nutritional Health? 330
Can Some Sun Exposure Be a Good Thing? 373
Is Folic Acid Fortification Good for Everyone? 415
How Much Water Do We Need? 446
Shaking the Habit 482
Does Drinking Unfluoridated Water Affect Dental Health? 515
Is Obesity a Disease? 542
Weighing the Pros and Cons of Gastric Bypass Surgery 584
Are Personal Trainers Reliable Sources of Credible Nutrition
Information? 626
Choosing Among Baby Foods 670
Are Schools Out to Lunch? 701
Protein: DRI Recommendations for Older Adults 734
Can Organic Go Large Scale? 786
Why Does Hunger Exist in the United States? 817
xxi

xxii
I am nothing without my ABCs.
Thanks.
—Joan Salge Blake
I dedicate this book to my family
for their love and support that sustained me through
the development of this book.
And to my students, both present and past,
for whom this book was written.
—Kathy D. Munoz
I would like to dedicate this book to
my Mom, Felicetta Volpe (in memory)
and my Dad, Antonio Volpe.
—Stella Lucia Volpe
101166 C P BC A Bl k P N 1 C/M/Y/K DESIGN SERVICES OF
A01_BLAK3199_01_SE_FM.QXD 7/21/09 10:20 AM Page 1

What Is
Nutrition?
1
1. Food choices are driven primarily by flavor. T/F
2. Cancer is the leading cause of death
in the United States. T/F
3. Eliminating all fat from the diet will improve health. T/F
4. Alcohol is a nutrient. T/F
5. The energy in foods is measured in kilocalories. T/F
6. Protein contains more
energy per gram than fat. T/F
M01_BLAK3199_01_SE_CH01.QXD 7/21/09 10:22 AM Page
2
?
7. The most effective method of nutritional
assessment is to ask a client to write down
what he’s eaten in the last 24 hours. T/F
8. You can get good nutrition advice
from anyone who calls himself a nutritionist. T/F
9. The number of obese Americans is lower today than

it was five years ago. T/F
10. As long as you take a vitamin pill, you don’t have to
worry about eating healthy food. T/F
See page 36 for answers.
3
4 Chapter 1 . What Is Nutrition?
Chapter Objectives
After reading this chapter, you will be
able to:
1. Discuss the factors that influence
food choice.
2. Define the term nutrition.
3. Describe how nutrition affects
health.
4. Name and explain the six classifi-
cations of nutrients found in food
and in the body.
5. Compare and contrast organic
and inorganic nutrients.

6. Differentiate between the three
energy nutrients.
7. Calculate the kilocalorie content
of a food based on the grams of
carbohydrate, protein, and lipids.
8. Discuss how to assess the nutri-
ent status of individuals and pop-
ulation groups.
9. Identify sources of accurate nutri-
tion information.
10. Discuss the current nutritional
state of the American diet.
Would you be surprised to learn that
Elizabeth did not do very well on her
exam? Do you, like Elizabeth, sometimes
eat snacks or other foods because you’re
stressed, rather than hungry? What other
factors influence your food choices?
In addition to exploring the factors
that can affect food choice, this chapter
will introduce you to the study of nutrition
and why it is so important to your health.
By the end of the chapter, you’ll be able
to identify sources of credible nutrition
information. Let’s start with the basic
concepts of why you choose the foods
you eat.
I

t’s the night before her final biology
exam, and Elizabeth, a junior, is in the
midst of a down-to-the-wire cram ses-
sion. She hasn’t opened her textbook for
weeks, so she is in high-stress mode.
Elizabeth pours herself a tall glass of caf-
feinated cola, opens up a family-size bag
of potato chips, and nervously plows
through the bag and the book. She
snacks and studies until the early hours
of the morning, and after a jittery 3 hours
of sleep, Elizabeth heads to her 8 a.m.
exam feeling tired, groggy, and still un-
comfortably stuffed from her potato chip-
and-soda cram session.
What Drives Our
Food Choices?
During the course of the day, we make over 200 decisions about
food, from when to
eat, how much to eat, and what to eat, to how the food is
prepared, and even what
plate to use.1 Have you ever considered what drives your food
choices? Or are you on
autopilot as you stand in line at the sub shop and squint at yet
another menu board?
What you choose to eat is both personal and complex and not
solely driven by the
need for sustenance. A multitude of interrelated factors affect
your food choices, be-
ginning with your personal preferences.
Taste and Enjoyment
Research confirms that when it comes to making food choices,
taste is the most im-

portant consideration.2 This shouldn’t be too much of a
surprise, considering there
are more than 10,000 taste buds in the mouth, mostly on the
tongue. Most people
prefer the taste of salty or sweet foods but the degree to which
we enjoy these foods
varies, partly because of genetics.3 Our enjoyment of sweet
foods also changes as we
age; infants and children prefer extremely sweet flavors, while
adults tend to enjoy
more subtle sweet flavors.4 Breast-fed babies whose mothers
eat a wide range of
foods are more likely to embrace new foods as adults, and
formula-fed infants re-
main more tolerant of bitter and sour tastes at age 4 or 5.5
Our taste for fat may also be genetically linked, although a gene
has not been
found that supports this theory.6 When fat is combined with
sugar, such as in a
sugar-laden doughnut, our taste for that food is even stronger.7
Texture also affects our likelihood of enjoying foods. We enjoy
a flaky pie crust
but dislike one that is tough; we prefer crunchy apples to mealy
ones, and creamy
rather than lumpy soups. Almost 30 percent of adults dislike
slippery foods, such as
oysters and okra.8 Researchers have suggested that these
preferences for sweetness,
high fat, and specific textures may have begun early in life and
this makes them re-
sistant to change.9
4

Culture and Environment
Enjoying food is not just a physiological sensation. Other fac-
tors, such as our culture and the environment, also play a role in
which foods we enjoy eating.10 What you choose to put on your
plate is often influenced by your culture. If you were a student
in
Mexico, you may regularly enjoy corn tortillas and tamales, as
corn is a staple of Mexican cuisines. In India, meals commonly
include lentils and other legumes with rice and vegetables,
whereas Native Americans often enjoy stews of mutton (sheep),
corn, vegetables, and berries. In China, rice likely would be
front
and center on your plate.
A culture’s cuisine is greatly influenced by the environment
in which its people live. Foods that are available and accessible
are more likely to be
regularly consumed than foods that are scarce. For example,
individuals who live
near coastal waters are much more likely to consume large
amounts of fresh seafood
in their diets than those who live in landlocked areas.
Our food environment—the variety of food choices available,
the size and shape
of plates and glassware, the packaging of foods, and the types
and amounts of food
visible—also has a strong influence on what and how much we
consume. We eat

more food when the serving plates are larger, or drink less when
beverages are served
in taller glassware. Environmental cues also affect eating
patterns. You are more
likely to linger over a meal when the light is dimmed, or
quickly finish your meal
when others at the table stop eating.11
Social Reasons and Trends
Eating is an important way to bond with others. For example,
the social interaction
between family and friends at holiday meals, such as
Thanksgiving, is one reason a
person is likely to eat more on Thanksgiving than on any other
Thursday of the year.
Eating dinner with others has been shown to increase the size of
the meal by over
40 percent, and the more people present, the more you’ll eat.12
Choosing to eat a
quick meal in the campus cafeteria may not be the best choice
for healthy food op-
tions, but it will allow you to socialize with classmates.
For many people, activities such as watching a football game
with fellow fans or
going to a movie with friends often involve particular foods.
More pizzas are sold on
Super Bowl Sunday than any other day of the year.13 Movie
theater owners bank on
their patrons buying popcorn, candy, and beverages at the
concession stand before
heading in to watch the film, and moviegoers are more likely to
buy these
snacks if they’re with a group of friends.14
Food choices are also affected by popular trends. For instance,

home
cooks in the 1950s bought bags of “newfangled” frozen
vegetables in
order to provide healthy meals in less time. A few decades later,
vegeta-
bles went upscale and consumers bought them as part of ready-
to-heat
stir-fry mixes. Today, shoppers pay a premium for bags of fresh
veggies,
like carrots, that have been prewashed and peeled, sliced, or
diced, and
they pay even more of a premium if the food is labeled
“organic.” In
2005 alone, Americans spent more than $51 billion on organic
or natu-
ral foods.15 Consumers also ate more plant-based products,
especially
from locally grown farmer’s markets, and ate more foods with
added
benefits, such as eggs with more omega-3 fatty acids or
calcium-fortified
orange juice.16
Environmental factors including
lighting at a meal, the size of a
package, and the shape of a glass
can influence the type and amount of
food you eat.
One in four Americans is of Hispanic, Native American, Asian,
or
African descent. Cultural food preferences often influence food
choices.
Eating junk food while watching sports
sometimes seems like an American way of life.

5
Weight Concerns, Body Image,
and Health Benefits
While the French take pleasure in cheese, bread, and high-fat
desserts, Americans worry
about fried eggs causing heart disease and butter-laden pastries
leading to obesity.
Hence, individuals may choose certain foods because they
perceive them as being
healthy, or avoid other foods that are associated with weight
gain or loss. Your percep-
tion of foods can be influenced by your current state of health.
For example, if you are
overweight, you are more likely to be aware of the kilocalorie
content of foods and avoid
foods that are high in fat and sugar.17 This can have a positive
effect on health as long as
body image concerns don’t become extreme and/or cause
disordered eating patterns.
The more aware you are of the effects of food choices on health,
the more likely
you will make an effort to improve your eating habits.18 The
fact that Americans are
eating less saturated and trans fats is directly related to the
perception that these
foods damage health. The net effect of this has been positive, as

more people have re-
duced their consumption of red meat, packaged snacks, and
processed foods, and in-
creased their intake of whole grains and whole fruits and
vegetables.19
Americans have also been consuming functional foods to
improve their
health since the late 1920s, when iodine was first added to salt.
Today’s functional
foods include whole foods such as oatmeal, genetically
modified foods that are de-
veloped to have a higher nutrient content, and foods that have
been fortified with
phytochemicals or added nutrients, such as calcium-fortified
orange juice. These
foods look, smell, and taste the same as regular foods but have
added health bene-
fits beyond their nutritional content. Although functional foods
can be beneficial,
consumers should not rely on them to replace other nutritious
whole foods in
their diet.
Advertising
Manufacturers spend $10 billion to $15 billion annually on food
advertising, with
over $700 million each year spent to market breakfast cereals,
candy, and gum. An-
other $500 million is spent to advertise carbonated soft
drinks.20 You probably saw at
least a few food ads as you surfed online, watched TV, or drove
to campus today. In
comparison, when was the last time you saw an advertisement
for broccoli? Have you
ever seen an ad for broccoli?

Food companies spend these large sums on advertising for one
reason: they
work, especially on young people.21 American children view up
to 40,000 televi-
sion commercials annually. On Saturday morning, more than
half of the between-
cartoon ads are for foods. Of these, over 40 percent are for
items such as candy, soft
drinks, chips, and sugary breakfast cereals.22
In contrast, commercials for fruits and vegetables are rare,
which is unfortunate,
because healthy foods can be successfully marketed. When the
dairy industry noted a
decline in milk consumption among Americans in 1994, it
launched the Got Milk? ad
campaign, which featured celebrities wearing milk mustaches.
This campaign strove
to make drinking milk sexy and it worked. Milk sales increased
by nearly 1.5 billion
pounds, which is the equivalent of about 45 pounds of milk
being sold for each ad-
vertising dollar spent.23
Time, Convenience, and Cost
When it comes to putting together a meal, time is often at a
premium, and Ameri-
cans, especially working women with families, want to spend
less than 15 minutes
The USDA certifies that organic
foods are grown without the use of
pesticides, herbicides, or chemical
fertilizers.

phytochemicals Nonnutritive plant
compounds, found in fruits and vegeta-
bles, that may play a role in fighting
chronic diseases.
functional foods Foods that may pro-
vide additional health benefits beyond the
basic nutrient value.
Rates of milk consumption increased
after the Got Milk? advertising
campaign.
6
preparing a meal.24 Consequently, supermarkets are offering
more prepared and par-
tially prepared foods. If chicken is on the menu tonight, you can
buy it uncooked at the
meat counter in the supermarket, or you can go to the deli and
buy it hot off the rotis-
serie, cooked and stuffed with bread crumbs, or grilled with
teriyaki sauce. The rice or
pasta side dishes and cooked vegetables are also available to
complete the meal.

Convenience has also become more of a factor in food selection.
Decades ago, the
most convenient way to get a hot cup of coffee was to brew it at
home. Today, Americans
are more likely to get their latte or half-caff from one of the
17,000 coffee shops, carts, and
kiosks across the United States (more than 7,000 of which are
Starbucks outlets).25, 26
For reasons related to both time and convenience, people are
eating out more
often today than they did a few decades ago. In the 1970s,
Americans spent about
25 percent of their household food budget on eating out,
compared with almost
45 percent today.27 Because cost is often an issue when
considering where to eat out,
most meals consumed away from home are fast food, which is
often cheaper and
quicker than more nutritious meals. Though cheap fast food may
be easy on the
pocketbook, it is taking its toll on the health of Americans.
Epidemiological research
suggests that low-cost, high-kilocalorie diets, such as those that
incorporate lots of
burgers, fries, tacos, and soft drinks, increase the risk of
obesity, especially among
those at lower socioeconomic levels.28 The long-term cost of
the additional weight
gain adds an estimated 36 percent to the annual cost of health
care.29
The good news is that cheaper food doesn’t have to always
mean fast food, and
when healthy foods are offered at lower prices, people do buy
them. Researchers

found that lowering the cost of fresh fruits, vegetables, and
lower fat snacks improves
the consumption of these nutritious foods.30 The study
demonstrates that price re-
ductions are an effective strategy to increase the purchase of
more healthful foods.
Results were consistent across various food types and
populations.
Habits and Emotions
Your daily routine and habits often affect both when you eat
and what you eat. For
example, if you routinely start your day with a bowl of cereal
and a glass of orange
juice, you’re not alone. Ready-to-eat cereals are the number-one
breakfast food
choice among Americans, and citrus juice is their top juice in
the morning.31 Many
individuals regularly snack when watching television or sitting
at the computer.32
For some individuals, emotions can sometimes drive food
choice, and feeling
happy or sad can trigger eating. In some cases, eating is
suppressed during periods of
sadness or depression. For many, food is used as an emotional
crutch during times of
stress, depression, or joy. Recall that Elizabeth ate her way
through a large bag of chips
before her exam. Her stress likely impaired her awareness of
how much she was eating.
The Take-Home Message Taste and enjoyment are the primary
rea-
sons people prefer certain foods. Food availability affects its
becoming part

of a culture, and many foods can be regularly eaten out of habit.
Advertising,
food trends, limited time, convenience, emotions, and the
perception that
foods are healthy or unhealthy also influence food choices.
Which of the factors you just learned about had the
strongestinfluence on Elizabeth’s food choices before her exam?
Do
you think her food choices had an impact on her test perfor -
mance? Why or why not?
Although brown rice is a healthy whole-grain
addition to any meal, it takes close to an hour
to cook. For time-strapped consumers, food
manufacturers have developed instant brown
rice that cooks in 10 minutes, and a precooked,
microwavable variety that reheats in less than
2 minutes.
7
made each day for meals, snacks, and
beverages. An example of the questions
the researchers asked included: “There
are many ‘when’ decisions you make with
food. You decide when to eat, when to
start cooking, when it is done cooking,
when to start serving, when to stop eat-

ing, and so on. Please try and estimate
how many of these ‘when’ decisions you
make in the following situations.”
Researchers also collected demo-
graphic data, including age, gender,
height, and weight, and used it to calcu-
late the body mass index (BMI) of each
participant. Normal weight was classified
as a BMI of less than 25 kilograms per
square meter; a BMI of greater than
25 kilograms per square meter was clas-
sified as overweight; and a BMI of greater
than 30 kilograms per square meter was
classified as obese.
In Study 2, 379 volunteers were
grouped into different, exaggerated con-
ditions in which their consumption behav-
ior was observed. These conditions in-
cluded larger package, serving bowl, and
plate sizes. Subjects were then asked
two questions: “How much did you eat
compared to what is typi-
cal for you?” and “In this
study, you were in a
group that was given [a
larger bowl]. Those peo-
ple in your group ate an
average of 20 to 50 per-
cent more than those
who were instead given
[a smaller bowl]. Why do
you think you might have
eaten more?”

Results
The results for Study 1
showed that initially most
participants made
14.4 food-and-beverage
decisions per day. When
asked more detailed questions related to
food consumption decisions, the number
rose to an average of 226.7 decisions per
day. The food decisions made by individ-
uals of various body weights indicated a
U-shaped relationship, with obese individ-
uals making significantly more food-
related decisions per day (more than
100 additional decisions) compared with
overweight subjects but similar to normal-
weight people in the study (see figure).
In Study 2, those participants who
were given an exaggerated amount of
food ate 31 percent more than the control
group. However, only 8 percent of these
subjects felt that they ate more than they
usually do. When these 8 percent were
told they overate, 21 percent claimed
they did not overeat. Of those subjects
who accepted they overate, 69 percent
said it was because they were hungry,
while only 4 percent attributed it to the
larger bowl or plate size.
Conclusions

The results from this research indicate
that subjects drastically underestimate
the number of food decisions they make
each day, and may be participating in
mindless eating. Normal-weight individu-
als make a similar number of food deci-
sions as obese individuals but appear
to make more “no”-related food-and-
beverage decisions. Tangible evidence
was presented that people are either un-
aware of how food decisions are being
influenced by environmental cues, or are
unwilling to accept that these cues play a
role in their decisions.
QUESTIONS
1. Were the measurements appropriate
to answer the research questions?
2. How do the results of this study an-
swer the research questions?
3. Are there other factors not measured
in this study that could have influenced
the results?
4. Do you agree with the authors’ con-
clusions?
Background
Most people are unaware of the amount
of food they consume throughout the
day. Their food consumption patterns are
often influenced by what they perceive to

be “normal,” which can be further af-
fected by the package or plate size, the
variety of food available, and the influence
of other people. Being unaware of the im-
pact of our environment as it affects food
intake can have implications on nutrition
education and food behavior research.
Research Question
There were two parts to the study. The
first part investigated how many food-
related decisions normal-weight, over-
weight, and obese people make during a
typical 24-hour period. The second part
looked into whether subjects were aware
that they overeat, and whether they were
influenced by environmental cues.
Study Design
Study 1 asked 154 college students and
adults to answer questions related to the
number of food decisions they make.
Subjects were asked, “How many total
food-and-beverage decisions do you
make in one day?” This was followed by
a series of 15 questions that related to
the number of when, what, how much,
where, and who with decisions they
Wansink, B. and J. Sobal. 2007. Mindless
Eating: The 200 Daily Food Decisions We
Overlook. Environment and Behavior
39:106–123.

FOCUS ON RESEARCH
0
50
100
150
200
250
300
350
400
Normal weight
Total decisions (calculated)
Beverage-related decisions
Meal-related decisions
Snack-related decisions
Initial estimate of decisions made
Weight of respondent
N
u
m
b

e
r
o
f
d
e
c
is
io
n
s
Overweight Obese
Calculated Number of Daily Food- and Beverage-Related
Decisions
8
nutrition The science that studies how
nutrients and compounds in foods nour-
ish the body and affect body functions and
overall health.

What Is Nutrition?
The science of nutrition is the study of food and the nutrients
we need to sustain life and
reproduce. It also explores the way food nourishes the body and
affects health.
The study of the relationship between food and health began as
early as the 1600s.
The term limey was coined after one of the earliest reported
nutrition discoveries: that
lime juice prevented scurvy (a disease caused by the lack of
vitamin C) in sailors. During
the 1700s, scientists recognized the value of what we ate in
treating disease so that by the
early 1900s the concept of essential nutrients had been widely
accepted. By the late nine-
teenth century, nutrition was becoming more quantitative,
addressing the question of
how much of each nutrient is required as well as accepting that
individuals vary in their
nutrient requirements. Nutritional epidemiology had been
developed by the end of the
twentieth century, and the advent of dietary surveys conducted
by the government was
used to further the science. The biochemistry of nutrition has
exploded since the
Human Genome Project in 2000. What began with British
sailors in the 1600s today in-
volves nutrition professionals, the government, and the food
industry as they strive to
develop new functional foods and nutraceuticals, and design
diets for longevity.
Since its inception, the science of nutrition has explored how
food is digested, ab-
sorbed, transported, metabolized, and used or stored in the

body. Nutritional scientists
study how much we need of each nutrient, the factors that
influence our needs, and
what happens if we don’t consume enough. A chronic deficiency
of even one nutrient
will impact the body’s ability to function in the short term, and
over time, chronic de-
ficiencies, excesses, and imbalances will affect long-term
health.
Good nutrition reduces the risk of four of the top ten leading
causes of death in
the United States, including the top three—heart disease,
cancer, and stroke—as well
as diabetes (Table 1.1). Nutrition also plays an important role in
preventing other
diseases and conditions that can impede one’s lifestyle. A
healthy diet, for example,
can keep bones strong and reduce the risk of developing
osteoporosis. Eating well
will also improve body weight, which in turn will reduce the
risk of developing obe-
sity, diabetes mellitus, and high blood pressure.
As with any science, nutrition is not stagnant. The more we
discover about the
relationship between nutrition and well-being, the greater the
impact will be on
long-term health.
The Take-Home Message Nutrition is the scientific study of
how the
nutrients and compounds in foods nourish the body. It has
evolved over the
past 400 years from a study of how nutrients relate to disease
into a science

that promotes health and longevity through a healthy diet. Good
nutrition re-
duces the risk of many chronic diseases, including heart disease,
cancer,
stroke, and diabetes.
What Are Nutrients?
The body is one large organism made up of millions of cells
that grow, age, repro-
duce, and die, all without your noticing. You slough off
millions of skin cells when
you towel off after a shower, yet your skin isn’t noticeably
thinner today than it was
last week. Your body replaces skin cells at a rate fast enough to
keep you covered, and
it manufactures new cells using the same nutrients found in a
variety of foods. As
cells die, nutrients from food provide the building blocks to
replace them. Nutrients
Table 1.1
Leading Causes
of Death in the
United States
Disease/
Cause of Death
Nutrition
Related
† 1. Heart Disease X
2. Cancer X

3. Stroke X
4. Respiratory Diseases
5. Accidents
6. Diabetes X
7. Influenza/Pneumonia
8. Alzheimer’s Disease
9. Kidney Disease
10. Blood Poisoning
Source: Centers for Disease Control: 2008. “National
Vital Statistics Report.” www.cdc.gov/nchs/data/nvsr/
nvsr56/nvsr56_10.pdf.
nutrients Compounds in foods that sus-
tain body processes. There are six classes of
nutrients: carbohydrates, fats (lipids), pro-
teins, vitamins, minerals, and water.
9
also provide the energy we need to perform all body functions
and processes, from
maintaining heart beat to playing tennis.

There are six categories of nutrients found in foods and in the
body: carbohy-
drates, lipids (fats), protein, vitamins, minerals, and water.
Foods also often contain
nonnutrient compounds, such as the phytochemicals mentioned
earlier, non-
digestible fiber, and other chemicals added by food
manufacturers to enhance color,
flavor, or texture, or extend shelf life.
About 10 percent of plant foods are made up of carbohydrates,
fats, protein, vi-
tamins, and minerals (Figure 1.1). The rest is typically water,
and plant foods contain
more water (90 percent) than do animal foods (60 percent). The
other 40 percent of
animal foods consist of protein, lipids, vitamins, and minerals.
One unique quality
of animal foods is that they do not contain any carbohydrates by
the time we con-
sume them.
In comparison with plant and animal products, a healthy human
body is 60 per-
cent water. The other 40 percent is made up of protein and fat,
as well as a small
amount of stored carbohydrates, minerals in the bone, and small
amounts of vita-
mins. Thus, the old saying is true: we are what we eat, from the
carbohydrates in
broccoli to the proteins in meat; the six biochemical ingredients
needed to sustain
life are all provided by the foods in our diets.
Most Nutrients Are Organic
Carbohydrates, proteins, lipids, and vitamins are the most

complex of the six classes
of nutrients. These nutrients are organic because their chemical
structures contain
carbon. Organic nutrients also contain the elements hydrogen
and oxygen, and in the
case of proteins and some vitamins, nitrogen is also part of the
molecule (Figure 1.2).
Minerals are the least complex of the nutrients and are
inorganic because their
chemical structure does not include carbon. Each mineral is an
individual element,
and its atoms are exactly the same whether found in food or in
the body. For in-
stance, the structure of zinc found in lean meats and nuts is the
same as that found in
a cell membrane or a hair follicle. Water, a three-atom molecule
comprised of hydro-
gen and oxygen, is also inorganic.
101166 C P BC A Bl k P N 10 C/M/Y/K DESIGN SERVICES
OF
20%
Human
body
60%
15%
Broccoli
(raw)

89%
7%
Chicken
breast
67%
30%
Water
Fats
Vitamins
Minerals
Carbohydrates
Protein
Fiber
Figure 1.1 Nutrients in Foods
and in the Body
Water is the most abundant nutrient found in
foods and in the body. Carbohydrates, fats,
proteins, vitamins, and minerals make up the
rest. Note that foods also contain nonnutritive
compounds, such as phytochemicals and
fiber.
inorganic Compounds that do not con-

tain carbon, such as minerals, water, and
salts.
organic Compounds that contain carbon
or carbon–carbon bonds.
Carbon
X
X
X
X
X
X
X
X
X
X
X
X
X
X

X
X
In
o
rg
a
n
ic
O
rg
a
n
ic
Hydrogen Oxygen Nitrogen
Single
elements
Some vitamins
contain nitrogen
Carbohydrates
Lipids
Proteins
Vitamins
Minerals

Water
Figure 1.2 The Chemical Composition of the Six Classifications
of Nutrients
in Food
Each nutrient contains a unique combination of chemical
elements.
10
OF
Most Nutrients Are Essential
In general, nutrients are essential and must come from foods,
because either they
cannot be made in the body, or they cannot be made in
sufficient amounts to meet
the body’s needs. A few nonessential nutrients can be made in
sufficient quantities
in the body. An example of this is vitamin D, which is
synthesized in the skin upon
exposure to sunlight. Under some circumstances, nonessential
nutrients can become
essential. In the case of vitamin D, if you are not exposed to
enough sunlight, you will
not be able to synthesize an adequate amount of the vitamin.
You must then obtain
vitamin D from foods.

Some Nutrients Provide Energy
All creatures need energy in order to function, and humans are
no exception. Energy
is defined as the capacity to do work, and also provides a source
of heat. The body
derives energy from certain nutrients in foods, which store
energy in their chemical
bonds. During digestion and metabolism, the bonds are broken,
and the energy is re-
leased. Carbohydrates, lipids (fats), and proteins are defined as
the energy-yielding
nutrients because they contribute energy to the body. Whereas
alcohol also provides
energy, it is not considered a nutrient because it doesn’t serve a
known function and
it interferes with the repair and maintenance of the body.
Energy Is Measured in Kilocalories
Kilocalorie is the term used by scientists to refer to the amount
of energy found in a
food. The term kilocalorie (kilo � 1,000) is defined as the
amount of energy needed
to raise the temperature of one kilogram of water 1 degree
Celsius. A kilocalorie is
not the same as a calorie (with a lowercase “c”), which is a
much smaller unit of mea-
surement. (In fact, a “calorie” is so small that one slice of bread
contains about
63,000 calories.) One kilocalorie is equal to 1,000 calories.
To add to the confusion, the term Calorie (with an uppercase
“C”) is used on
nutrition labels to express the energy content of foods and is
often used in science
textbooks to reflect kilocalories. This textbook will refer to the
units of energy found

in foods as kilocalories, abbreviated kcalories or kcals.
Calculating the Energy in Foods
Each energy-yielding nutrient provides a set number of
kilocalories per gram, thus
the number of kilocalories in one serving of a given food can be
determined based
on the amount (weight, in grams) of carbohydrates, protein, and
fat in the food. For
example, carbohydrates and protein provide 4 kilocalories per
gram, so a food that
contains 5 grams of carbohydrate and 3 grams of protein would
have 32 kilocalories
([5 � 4] � [3 � 4] � 32). Fats yield 9 kilocalories per gram, or
more than twice the
number of kilocalories in either carbohydrates or protein.
Alcohol contains 7 kilo-
calories per gram, which must be taken into account when
calculating the energy of
alcohol-containing foods and beverages (Figure 1.3).
Use the Calculation Corner box on the next page to determine
the number of
kilocalories in Elizabeth’s potato-chip-and-cola snack.
nonessential nutrients Nutrients that
can be made in sufficient quantities in the
body to meet the body’s requirements and
support health.
essential [nutrients] Nutrients that
must be consumed from foods because
they cannot be made in the body in suffi-

cient quantities to meet its needs and sup-
port health.
Most nutrients consist of carbon, hydro-
gen, and oxygen. These elements com-
bine to form compounds through
chemical reactions. An atom of each ele-
ment can form a set number of bonds
with other elements. For example, carbon
can form bonds with four elements, hy-
drogen can form one bond, and oxygen
can form two bonds, as illustrated below.
When two atoms bond together to form a
compound, they are called molecules.
Molecules tend to be more stable than
atoms, and, like atoms, can carry a posi-
tive or negative charge. Charged atoms
or molecules are called ions.
H
H—C—H H—O—H
H
—
—
Chemistry Boost
energy The capacity to do work.
kilocalorie The amount of energy required
to raise the temperature of 1 kilogram of

water 1 degree centigrade; used to express the
measurement of energy in foods; 1 kilocalorie
is equal to 1,000 calories.
energy-yielding nutrients The three
nutrients that provide energy to the body
to fuel physiological functions: carbohy-
drates, lipids, and protein.
11
OF
Elizabeth ate an entire bag of potato chips and drank a 16-ounce
cola while she studied for her exam.
Together these two items contain 144 grams of carbohydrate (in
the cola and chips), 12 grams of pro-
tein (from the chips), and 60 grams of fat (also in the chips).
How many kilocalories did she consume?
(a) To calculate the total kilocalories in Elizabeth’s snack,
multiply the total grams of each energy
nutrient times the number of kilocalories per gram of that
nutrient. Remember, a gram of carbohy-
drate and protein each contain 4 kilocalories and a gram of fat

contains 9 kilocalories.
(144 g � 4 kcals/g) � (12 g � 4 kcals/g) � (60 g � 9 kcals/g)
� 1,164 kcals
576 kcals � 48 kcals � 540 kcals � 1,164 kcals
In one sitting, Elizabeth consumed more than 1,100 kilocalories,
or more than half of the
amount she likely needs to meet her daily energy requirement.
As you’ll learn in later chapters, if
behaviors like this become habits, they can quickly result in
weight gain.
(b) Another useful measure for assessing the nutritional quality
of Elizabeth’s snack is the percent-
age of fat, protein, and/or carbohydrate found in the food (you
will learn in later chapters that there
are ranges for each nutrient that are considered part of a healthy
diet). For example, what percent
of kilocalories in the chips and soda is from fat? To answer this
question, divide the fat kilocalories
by the total kilocalories in the food and multiply by 100:
(540 kcals � 1,164 kcals) � 100 � 46% fat
Almost half of the kilocalories in Elizabeth’s snack are from
fat. Do you think this is likely to be a de-
sirable proportion?
For practice, complete the same calculations for carbohydrate
and protein.
C A L C U L AT I O N C O R N E R
Energy in the Body

Energy in foods and in the body is trapped within the bonds that
keep the molecules
together. When the bonds are broken, such as during the process
of metabolism, a
significant amount of energy, including some heat, is released.
The energy can then
Figure 1.3 Nutrients and Alcohol
Provide Kilocalories to Fuel the Body
Carbohydrates, fats, protein, and alcohol
provide energy, or kilocalories.
Carbohydrates
4 kcal/g
Alcohol
7 kcal/g
Fats
9 kcal/g
Protein
4 kcal/g
12
What Are the Primary Roles of the Individual Nutrients? 13
OF
be used to digest and absorb the meal, contract muscles, fuel the
heart, and synthe-

size new cells, as well as other functions.
People’s energy needs vary according to their age, gender, and
activity level.
Males generally need more energy because they weigh more,
and have more muscle
mass (which requires more kilocalories to function) and less
body fat. A younger per-
son requires more energy than an older adult because he is still
growing and is there-
fore synthesizing more new tissue. Physically active individuals
require more energy
than sedentary people to fuel their activities and meet their
body’s basic energy needs.
Energy that is not used to fuel the body will be rearranged into
storage forms for
later use, predominantly as fat. If you regularly consume more
kilocalories than you
expend, you will accumulate stored fat in adipose tissue and
gain weight. The oppo-
site is also true. Eating fewer kilocalories than the body needs
will result in the break-
down of stored energy and weight loss.
The Take-Home Message The nutrients found in foods are used
by
the body to manufacture and replace cells. Carbohydrates,
lipids, proteins,
and vitamins are organic nutrients composed of the chemical
elements car-
bon, hydrogen, oxygen, and sometimes nitrogen. Minerals and
water are
inorganic. Minerals are comprised of single atoms and water is
made up of hy-
drogen and oxygen. Energy in foods is measured in kilocalories.

The energy-
yielding nutrients, carbohydrates (4 kilocalories per gram),
lipids (9 kilocalories
per gram), and proteins (4 kilocalories per gram), provide fuel
to be used by
the body or stored for future use. Alcohol (7 kilocalories per
gram) is not a nu-
trient but does provide energy.
What Are the Primary
Roles of the Individual
Nutrients?
Individual nutrients serve unique roles in the body. They supply
energy, regulate metab-
olism, and provide structure (Table 1.2). Some nutrients,
including carbohydrates,
lipids, proteins, and water, are called macronutrients (macro �
large) because they are
needed in much larger amounts to support normal functioning.
Vitamins and minerals,
Table 1.2
Functions of the Major Nutrients by Type
Nutrient
Provides
Energy
Participates in Growth,
Maintenance,
Support, or Structure
Regulates
Body
Processes

Macronutrients Carbohydrates Yes No No
Protein Yes Yes Yes
Fats Yes Yes Yes
Water No Yes Yes
Micronutrients Vitamins No Yes Yes
Minerals No Yes Yes
macronutrients Organic nutrients, in-
cluding the energy-containing carbohy-
drates, lipids, proteins, and water that the
body needs in large amounts.
Converting Pounds
to Kilograms
Some of the calculations used in nutrition re-
quire conversion of body weight from pounds to
kilograms (kg). For example, one common cal-
culation for the recommended intake for protein
uses kilograms (although there are also formu-
las using pounds).
To determine how many kilograms Elizabeth
weighs, use her weight in pounds (125 pounds)
and divide by the conversion factor 2.2:
125 lb � 2.2 � 56.8 kg

Using your own body weight in pounds, calcu-
late your weight in kilograms.
C A L C U L AT I O N C O R N E R
13
though equally important to health, are considered
micronutrients (micro � small) be-
cause they are required in smaller amounts to perform their key
roles.
Each of the six classifications of nutrients will briefly be
introduced in this chap-
ter, and then discussed in much greater detail later in the
textbook.
Carbohydrates Are the Primary
Energy Source
Carbohydrates are the body’s main source of energy. All forms
of carbohydrates are
composed of carbon (carbo-), hydrogen, and oxygen (hydrate �
water). Carbohy-
drates supply the simple sugar, glucose, which is the primary
source of energy for
several body cell types, including red blood cells and brain
cells. Carbohydrates are
found in most foods. Breads, cereals, legumes, nuts, fruits,
vegetables, and dairy
products are all rich in carbohydrates. The only foods that do
not provide significant
amounts of carbohydrates are animal products other than dairy,
such as eggs, meat,

poultry, and fish. Carbohydrates will be covered in detail in
Chapter 4.
Lipids Also Provide Energy
The term lipid refers to a diverse group of organic compounds
including fats (also
called triglycerides), oils, phospholipids, and sterols that are
insoluble in water. These
nutrients contain the same chemical elements as carbohydrates,
including carbon,
hydrogen, and oxygen. The difference is that lipids are much
more concentrated than
carbohydrates and contain less oxygen and water.
Lipids in the form of triglycerides are an important energy
source for the body,
especially during rest and sleep. This is also the form in which
the body stores excess
energy. The stored energy makes up the adipose tissue beneath
the skin and around
several organs.
Triglycerides make up the majority of the lipids we eat and
are found in margarine, butter, oils, and animal products.
Chapter 5 will present more information on lipids.
Proteins Provide
the Building Blocks
for Tissue Synthesis
Proteins can be used for energy but are usually not the primary
energy source. Proteins are similar in composition to carbohy-
drates and lipids in that they contain carbon, hydrogen, and
oxy-
gen. But they are unique in that all proteins contain the element
nitrogen, and some also contain sulfur.

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