The Appendixes The appendixes are valuable references for a number of purposes. Appendix A summarizes background information on the hormonal and nervous systems, Because nutrition is an active science, staying current is paramount.
To that end, this edition builds on the science of previous editions with the latest in nutrition research. The number of foods has increased dramatically—even as we spend less time than ever in the kitchen preparing meals. The connections between diet and disease have become more apparent—and consumer interest in making smart health choices has followed.
More people are living longer and healthier lives. In this edition, as with all previous editions, every chapter has been revised to enhance learning by presenting current information accurately and attractively. Videos are available as pop-up tutors in the e-book and can be downloaded to an iPod or other portable device. The Student Course Guide features chapter and video assignments, lesson overviews, chapter learning objectives, key lesson concepts, and a practice test for each lesson.
Test Bank: The test bank features a large assortment of multiple-choice questions categorized by knowledge or application , essay questions, and matching exercises, now organized by chapter section title for easier item selection.
For Canadian adopters, the manual contains a Canadian information section with equivalencies, nutrient recommendations, and more. Included is a correlation guide to assist you in utilizing the transparencies from the tenth, eleventh, and twelfth editions together for the most comprehensive coverage.
Students can access study tools and complete exercises including critical-thinking questions and case studies online for quick e-mail submission to instructors. Closing Comments We have taken great care to provide accurate information and have included many references at the end of each chapter and highlight. However, to keep the number of references manageable, many statements that appeared in previous editions with references now appear without them.
Nutrition is a fascinating subject, and we hope our enthusiasm for it comes through on every page. Ellie Whitney Sharon Rady Rolfes October xviii Acknowledgments To produce a book requires the coordinated effort of a team of people—and, no doubt, each team member has another team of support people as well.
We salute, with a big round of applause, everyone who has worked so diligently to ensure the quality of this book. We thank our partners and friends, Linda DeBruyne and Fran Webb, for their valuable consultations and contributions; working together over the past plus years has been a most wonderful experience. Special thanks to our colleagues Kathy Pinna for her insightful comments and Gail Hammond for her Canadian perspective.
Thanks also to Lauren Tarson, Shelly Ryan, Elesha Feldman, and the folks at Axxya Systems for their assistance in creating the food composition appendix and developing the computerized Diet Analysis Plus program that accompanies this book. To the hundreds of others involved in production and sales, we tip our hats in appreciation.
We are especially grateful to our friends and families for their continued encouragement and support. We also thank our many reviewers for their comments and contributions. WithThroughout this chapter, the CengageNOW logo indicates an opportunity for online self-study, linking you to interactive tutorials, activities, and videos to increase your understanding of chapter concepts. How successfully your body handles these tasks depends, in part, on your food choices. Nutritious food choices support healthy bodies.
And it will continue to affect you in major ways, depending on the foods you select. Of course, some people will become ill or die young no matter what choices they make, and others will live long lives despite making poor choices. Although most people realize that their food habits affect their health, they often choose foods for other reasons. After all, foods bring to the table a variety of pleasures, traditions, and associations as well as nourishment.
The challenge, then, is to combine favorite foods and fun times with a nutritionally balanced diet. By comparison, an acute disease develops quickly, produces sharp symptoms, and runs a short course. A variety of food choices can support good health, and an understanding of human nutrition helps you make sensible selections more often.
Two widely shared preferences are for the sweetness of sugar and the savoriness of salt. Liking high-fat foods also appears to be a universally common preference. Other preferences might be for the hot peppers common in Mexican cooking or the curry spices of Indian cuisine. Research nutrition: the science of foods and the nutrients and other substances they contain, and of their actions within the body including ingestion, digestion, absorption, transport, metabolism, and excretion.
Habit People sometimes select foods out of habit. They eat cereal every morning, for example, simply because they have always eaten cereal for breakfast. Eating a familiar food and not having to make any decisions can be comforting. People eat the foods they grew up eating. Every country, and in fact every region of a country, has its own typical foods and ways of combining them into meals.
This is most evident when eating out: 60 percent of U. Chapter 9 describes how people tend to eat more food when socializing with others.
Meals are often social events, and sharing food is part of hospitality—regardless of hunger signals. Social customs invite people to accept food or drink offered by a host or shared by a group. An enjoyable way to learn about other cultures is to taste their ethnic foods. Consumers who value convenience frequently eat out, bring home ready-to-eat meals, or have food delivered.
Alternatively, some consumers visit meal-preparation businesses where they can assemble several meals to feed their families from ingredients that have been purchased and portioned according to planned menus.
Eating a banana or a candy bar may be equally convenient, but the fruit provides more vitamins and minerals and less sugar and fat. They are less likely to buy higher priced convenience foods and more likely to buy less-expensive store brand items and prepare home-cooked meals. In fact, more than 80 percent of U. By the same token, people can develop aversions and dislike foods that they ate when they felt sick or that they were forced to eat as a child.
By using foods as rewards or punishments, parents may inadvertently teach their children to like and dislike certain foods. Emotions Some people cannot eat when they are emotionally upset. Others may eat in response to a variety of emotional stimuli—for example, to relieve boredom or depression or to calm anxiety.
A depressed person may choose to eat rather than to call a friend. A person who has returned home from an exciting evening out may unwind with a late-night snack. Carbohydrate and alcohol, for example, tend to calm, whereas protein and caffeine are more likely to activate.
Eating in response to emotions can easily lead to overeating and obesity, but it may be appropriate at times. For example, some Christians forgo meat on Fridays during Lent the period prior to Easter , Jewish law includes an extensive set of dietary rules that govern the use of foods derived from animals, and Muslims fast between sunrise and sunset during Ramadan the ninth month of the Islamic calendar.
Some vegetarians select foods based on their concern for animal rights. A concerned consumer may boycott fruit picked by migrant workers who have been exploited. People may buy vegetables from local farmers to save the fuel and environmental costs of foods shipped from far away.
They may also select foods packaged in containers that can be reused or recycled. To contributions are called functional foods. These foods must also taste good—as good as the traditional choices.
A person selects foods for a variety of reasons. Biologically speaking, people eat to receive nourishment. Do you ever think of yourself as a biological being made of carefully arranged atoms, molecules, cells, tissues, and organs? Are you aware of the activity going on within your body phytochemicals FIE-toe-KEM-ih-cals : nonnutrient compounds found in plant-derived foods that have biological activity in the body.
The atoms, molecules, and cells of your body continuously move and change, even though the structures of your tissues and organs and your external appearance remain relatively constant. Your skin, which has covered you since your birth, is replaced entirely by new cells every 7 years. The fat beneath your skin is not the same fat that was there a year ago. Your oldest red blood cell is only days old, and the entire lining of your digestive tract is renewed every 3 to 5 days. Foods bring pleasure—and nutrients.
Nutrients in Foods and in the Body Amazingly, our bodies can derive all the energy, structural materials, and regulating agents we need from the foods we eat. This section introduces the nutrients that foods deliver and shows how they participate in the dynamic processes that keep people alive and well. Nutrient Composition of the Body A chemical analysis of your body would show that it is made of materials similar to those found in foods see Figure FIGURE Body Composition of Healthy-Weight Men and Women The human body is made of compounds similar to those found in foods—mostly water 60 percent and some fat 13 to 21 percent for young men, 23 to 31 percent for young women , with carbohydrate, protein, vitamins, minerals, and other minor constituents making up the remainder.
Chapter 8 describes the health hazards of too little or too much body fat. The energy in food is chemical energy. The body can convert this chemical energy to mechanical, electrical, or heat energy. Nutrients may also reduce the risks of some diseases. The remaining pounds are mostly protein, carbohydrate, and the major minerals of the bones. Vitamins, other minerals, and incidental extras constitute a fraction of a pound.
Chemical Composition of Nutrients The simplest of the nutrients are the min- erals. Each mineral is a chemical element; its atoms are all alike.
As a result, its identity never changes. For example, iron may have different electrical charges, but the individual iron atoms remain the same when they are in a food, when a person eats the food, when the iron becomes part of a red blood cell, when the cell is broken down, and when the iron is lost from the body by excretion.
The next simplest nutrient is water, a compound made of two elements—hydrogen and oxygen. Minerals and water are inorganic nutrients, which means they do not contain carbon. The other four classes of nutrients carbohydrates, lipids, proteins, and vitamins are more complex. In addition to hydrogen and oxygen, they all contain carbon, an element found in all living things. As Chapter 19 explains, organic farming refers to growing crops and raising livestock according to standards set by the U.
Protein and some vitamins also contain nitrogen and may contain other elements such as sulfur as well see Table Essential Nutrients The body can make some nutrients, but it cannot make all of them. The nutrients that foods must supply are essential nutrients. The Energy-Yielding Nutrients: Carbohydrate, Fat, and Protein In the body, three organic nutrients can be used to provide energy: carbohydrate, fat, and protein.
Energy Measured in kCalories The energy released from carbohydrate, fat, and protein can be measured in calories—tiny units of energy so small that a single apple provides tens of thousands of them.
About 40 nutrients are currently known to be essential for human beings. In contrast, vitamins and minerals are micronutrients, required only in small amounts milligrams or micrograms daily. Food energy is measured in kilocalories calories equal 1 kilocalorie , abbreviated kcalories or kcal.
To convert kcalories to kilojoules, multiply by 4. Through such experiences, a person can become familiar with a measure without having to do any conversions. In addition to using metric measures, the SI establishes common units of measurement.
For example, the SI unit for measuring food energy is the joule not the kcalorie. A joule is the amount of energy expended when 1 kilogram is moved 1 meter by a force of 1 newton. The joule is thus a measure of work energy, whereas the kcalorie is a measure of heat energy. To convert energy measures from kcalories to kilojoules, multiply by 4.
For additional practice log on to www. Volume: Liters L A liter of liquid is approximately one U. Four liters are only about 5 percent more than a gallon. TRY Convert your body weight from pounds to kilograms and your height from inches to centimeters. Then add the results together. Knowing that this snack provides 47 percent of its kcalories from fat alerts a person to the need to make lower-fat selections at other times that day.
TRY Calculate the energy available from a bean burrito with cheese 55 grams car- IT bohydrate, 15 grams protein, and 12 grams fat. Determine the percentage of kcalories from each of the energy nutrients. Energy from Foods The amount of energy a food provides depends on how much carbohydrate, fat, and protein it contains. Because fat provides more energy per gram, it has a greater energy density than either carbohydrate or protein. Figure p. Alcohol, however, is not considered a nutrient.
Unlike the essential nutrients, alcohol does not sustain life. In fact, it interferes with the growth, maintenance, and repair of the body. Its only common characteristic with nutrients is that it yields energy 7 kcalories per gram when metabolized in the body. Most foods contain all three energy-yielding nutrients, as well as vitamins, minerals, water, and other substances. For example, meat contains water, fat, vitamins, and minerals as well as protein. Bread contains water, a trace of fat, a little protein, and some vitamins and minerals in addition to its carbohydrate.
Only a few foods are exceptions to this rule—the common ones being sugar pure carbohydrate and oil essentially pure fat. Energy in the Body The body uses the energy-yielding nutrients to fuel all its activities. As the bonds break, they release energy. Thus the energy from food supports every activity from quiet thought to vigorous sports. Both of these breakfast options provide kcalories, but the cereal with milk, fruit salad, scrambled egg, turkey sausage, and toast with jam offers three times as much food as the doughnuts based on weight ; it has a lower energy density than the doughnuts.
Selecting a variety of foods also helps to ensure nutrient adequacy. If the body does not use these nutrients to fuel its current activities, it converts them into storage compounds such as body fat to be used between meals and overnight when fresh energy supplies run low. If more energy is consumed than expended, the result is an increase in energy stores and weight gain. Similarly, if less energy is consumed than expended, the result is a decrease in energy stores and weight loss.
When consumed in excess of energy needs, alcohol, too, can be converted to body fat and stored. Highlight 7 describes the effects of alcohol on health and nutrition.
Proteins are found in structures such as the muscles and skin and help to regulate activities such as digestion and energy metabolism. Chapter 6 presents a full discussion on proteins. The Vitamins The vitamins are also organic, but they do not provide energy. Instead, they facilitate the release of energy from carbohydrate, fat, and protein and participate in numerous other activities throughout the body.
Each of the 13 vitamins has its own special roles to play. When you cut yourself, one vitamin helps stop the bleeding and another helps repair the skin.
Vitamins busily help replace old red blood cells and the lining of the digestive tract. Almost every action in the body requires the assistance of vitamins. The fat-soluble vitamins are vitamins A, D, E, and K. The watersoluble vitamins are the subject of Chapter 10 and the fat-soluble vitamins, of Chapter This is why the body handles them carefully and why nutrition-wise cooks do, too. The strategies of cooking vegetables at moderate temperatures for short times and using small amounts of water help to preserve the vitamins.
The Minerals In the body, some minerals are put together in orderly arrays in such structures as bones and teeth.
Whatever their roles, minerals do not yield energy. Only 16 minerals are known to be essential in human nutrition. Still other minerals, such as lead, are environmental contaminants that displace the nutrient minerals from their workplaces in the body, disrupting body functions. The problems caused by contaminant minerals are described in Chapter Because minerals are inorganic, they are indestructible and need not be handled with the special care that vitamins require.
It participates in many metabolic reactions and supplies the medium for transporting vital materials to cells and carrying waste products away from them. Water is discussed fully in Chapter 12, but it is mentioned in every chapter. Energy is measured in kcalories. Vitamins, minerals, and water facilitate a variety of activities in the body. Without exaggeration, nutrients provide the physical and metabolic basis for nearly all that we are and all that we do.
The next section introduces the science of nutrition with emphasis on the research methods scientists have used in uncovering the wonders of nutrition. Its foundation depends on several other sciences, including biology, biochemistry, and physiology.
And it is currently experiencing a tremendous growth spurt as scientists apply knowledge gained from sequencing the human genome. Chapters 12 and 13 are devoted to the major and trace minerals, respectively. Some minerals are essential nutrients required in small amounts by the body for health.
The study of genomes is called genomics. Thus the sequence begins anew, and research continues in a somewhat cyclical way.
Develop a theory that integrates conclusions with those from numerous other studies. Epidemiological studies include cross-sectional, casecontrol, and cohort see Figure Laboratory-based studies are often conducted in test tubes in vitro or on animals. Because each type of study has strengths and weaknesses, some provide stronger evidence than others see Table Some examples of various types of research designs are presented in Figure p. In attempting to discover whether a nutrient relieves symptoms or cures a disease, researchers deliberately manipulate one variable for example, the amount of vitamin C in the diet and measure any observed changes perhaps the number of colds.
As much as possible, all other conditions are held constant. The following paragraphs illustrate how this is accomplished. Controls In studies examining the effectiveness of vitamin C, researchers typi- cally divide the subjects into two groups.
One group the experimental group receives a vitamin C supplement, and the other the control group does not. Researchers observe both groups to determine whether one group has fewer, milder, or shorter colds than the other. The following discussion describes some of the pitfalls inherent in an experiment of this kind and ways to avoid them.
In sorting subjects into two groups, researchers must ensure that each person has an equal chance of being assigned to either the experimental group or the control group. Ideally, the control group receives a placebo while the experimental group receives a real treatment. If A increases as B increases, or if A decreases as B decreases, the correlation is positive. This does not mean that A causes B or vice versa.
If A increases as B decreases, or if A decreases as B increases, the correlation is negative. This does not mean that A prevents B or vice versa. Some third factor may account for both A and B. The experimental group receives the real treatment. Blood cholesterol Researchers compare people who do and do not have a given condition such as a disease, closely matching them in age, gender, and other key variables so that differences in other factors will stand out.
These differences may account for the condition in the group that has it. Many people in the Mediterranean region drink more wine, eat more fat from olive oil, and yet have a lower incidence of heart disease than northern Europeans and North Americans. Researchers analyze data collected from a selected group of people a cohort at intervals over a certain period of time. Data collected periodically over the past several decades from over people randomly selected from the town of Framingham, Massachusetts, in have revealed that the risk of heart attack increases as blood cholesterol increases.
People with goiter lack iodine in their diets. Such studies test possible disease causes and treatments in a laboratory where all conditions can be controlled. Mice fed a high-fat diet eat less food than mice given a lower-fat diet, so they receive the same number of kcalories—but the mice eating the fat-rich diet become severely obese.
These trials help determine the effectiveness of such interventions on the development or prevention of disease. Heart disease risk factors improve when men receive fresh-squeezed orange juice daily for two months compared with those on a diet low in vitamin C—even when both groups follow a diet high in saturated fat.
Importantly, the two groups of people must be similar and must have the same track record with respect to colds to rule out the possibility that observed differences in the rate, severity, or duration of colds might have occurred anyway.
In experiments involving a nutrient, the diets of both groups must also be similar, especially with respect to the nutrient being studied. Statistical methods are used to determine whether differences between groups of various sizes support a hypothesis. Placebos If people who take vitamin C for colds believe it will cure them, their chances of recovery may improve. This phenomenon, the result of expectations, is known as the placebo effect.
Severity of symptoms is often a subjective measure, and people who believe they are receiving treatment may report less-severe symptoms. One way experimenters control for the placebo effect is to give pills to all participants. Those in the experimental group, for example, receive pills containing vitamin C, and those in the control group receive a placebo—pills of similar appearance and taste containing an inactive ingredient. This way, the expectations of both groups will be equal.
It is not necessary to convince all subjects that they are receiving vitamin C, but the extent of belief or unbelief must be the same in both groups.
A study conducted under these conditions is called a blind experiment—that is, the subjects do not know are blind to whether they are members of the experimental group receiving treatment or the control group receiving the placebo.
Double Blind When both the subjects and the researchers do not know which subjects are in which group, the study is called a double-blind experiment. To prevent such bias, the pills are coded by a third party, who does not reveal to the experimenters which subjects are in which group until all results have been recorded.
Scientists must be cautious about drawing any conclusions until they have accumulated a body of evidence from multiple studies that have used various types of research designs. Correlations and Causes Researchers often examine the relationships between two or more variables—for example, daily vitamin C intake and the number of colds or the duration and severity of cold symptoms.
Importantly, researchers must be able to observe, measure, or verify the variables selected. Findings sometimes suggest no correlation between variables regardless of the amount of vitamin C consumed, the number of colds remains the same. Correlational evidence proves only that variables are associated, not that one is the cause of the other. People often jump to conclusions when they notice correlations, but their conclusions are often wrong.
This raises an important point regarding information found on the Internet: much gets published without the rigorous scrutiny of peer review.
Highlight 1 offers guidance in determining whether website information is reliable. Table describes the parts of a typical research article. The abstract provides a brief overview of the article. The introduction clearly states the purpose of the current study. A comprehensive review of the literature reveals all that science has uncovered on the subject to date. Usually, they answer a few questions and raise several more.
Highlight 5 provides a detailed look at how dietary fat recommendations have evolved over the past several decades as researchers have uncovered the relationships between the various kinds of fat and their roles in supporting or harming health. In designing their studies, researchers randomly assign control and experimental groups, seek large sample sizes, provide placebos, and remain blind to treatments. Such research has laid the foundation for quantifying how much of each nutrient the body needs.
These recommendations apply to healthy people and may not be appropriate for people with diseases that increase or decrease nutrient needs. The committee selects a different criterion for each nutrient based on its roles in supporting various activities in the body and in reducing disease risks.
The tables of DRI Dietary reference intakes are also present in the book. So while studying nutrition we can have a accurate picture of amount of food suitable for us. Understanding Nutrition is a quite lengthy book. It contains more than thousand pages. The nutrition book is also available in 13th edition. There are twenty full length chapters in the book. Like the book personal nutrition, this book also encircles all the major aspects of human nutrition.
Genres: Health and Fitness. Nutrition is a science. When the science is explained step by step and the facts are connected one by one, the details become clear and understandable.
By telling stories about fat mice, using analogies of lamps, and applying guidelines to groceries, we make the science of nutrition meaningful and memorable. We have learned from the thousands of professors and more than a million students who have used this book through the years that readers want an understanding of nutrition so they can make healthy choices in their daily lives. The early chapters introduce the nutrients and their work in the body, and the later chapters apply that information to people?
The mission of this text is to reveal the fascination of science in nutrition and provide readers with an understanding of nutrition so that they can make healthy choices in their daily lives. Packaged with the Dietary Guidelines, the 14th Edition includes new and updated topics in every chapter, quick-reference tables, expansive weight loss information, thorough coverage of fitness and energy systems, and much more.
Readers quickly connect with the text's approachable writing style and carefully developed art program, and its emphasis on active learning includes a rich variety of ways to help you put what you learn into action.
In addition, through the MindTap for Nutrition companion online program, you can create a customizable learning path to walk you step by step through the course. This text includes 20 chapters beginning with core nutrition topics; such as, diet planning, macronutrients, vitamins and minerals, and following with chapters on diet and health, fitness, life span nutrition, food safety, and world hunger. With its focus on Australia and New Zealand, the text incorporates current nutrition guidelines, recommendations and public health nutrition issues relevant to those studying and working in nutrition in this region of the world.
A thorough introductory guide, this market-leading text equips students with the knowledge and skills required to optimise health and wellbeing. The text begins with core nutrition topics, such as diet planning, macronutrients, vitamins and minerals, and follows with chapters on diet and health, fitness, life span nutrition and food safety.
Praised for its consistent level and readability, careful explanations of all key topics including energy metabolism and other complex processes , this is a book that connects with students, engaging them as it teaches them the basic concepts and applications of nutrition.
Role Development in Professional Nursing Practice, Third Edition examines the progression of the professional nursing role and provides students with a solid foundation for a successful career. This essential resource includes recommendations from current research and utilizes a comprehensive competency model as its framework.
Navigate eFolio transforms how students learn and instructors teach by bringing together authoritative and interactive content aligned to course objectives, with student practice activities and assessments, an ebook, and reporting tools For more information visit go. Understanding Nutrition is a practical and engaging introduction to the core principles of nutrition.
Building upon Ellie Whitney and Sharon Rady Rolfesa classic text, this second Australian and New Zealand edition equips students to optimise health and wellbeing. With its focus on Australia and New Zealand, the text incorporates current nutrition guidelines, recommendations and public health nutrition issues relevant to this region of the world. This textbook is praised for consistent level and readability, and careful explanations of all key topics including energy metabolism and other complex processes.
It opens with core nutrition topics, such as diet planning, macronutrients, vitamins and minerals, and follows with chapters on diet and health, fitness, life span nutrition and food safety.
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