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Chapter 1
Introduction to Nutrition
Chapter 1 Learning Outcomes
1.1 The Importance of Nutrition
1.1.1 Explain why it is important to study nutrition.
1.1.2 Describe Americans’ current food-buying practices and how they compare to dietary
recommendations
1.2 The Nutrients
1.2.1 List the six classes of nutrients and identify major roles of each class of nutrient in the
body.
1.2.2 Identify the key features of an essential nutrient.
1.2.3 Categorize nutrients based on whether they are essential and their designation as
micronutrients or macronutrients.
1.2.4 Identify rich food courses of phytochemicals.
1.3 Food as Fuel
1.3.1 Distinguish between calorie and kilocalorie.
1.3.2 Estimate the amount of energy (kcal) in a serving of food based on the grams of
carbohydrate, protein, fat, and alcohol present.
1.4 Does Diet Matter?
1.4.1 Identify the leading causes of death in the United States.
1.4.2 Describe lifestyle factors that contribute to the leading causes of death in the United
States.
1.4.3 Identify nutrition-related objectives of Healthy People 2020.
1.5 Factors That Influence Eating Habits
1.5.1 Identify factors that influence a person’s usual food selections.
1.5.2 Discuss the influence that biological, physiological, cognitive, and psychological factors
can have on a person’s food choices.
1.5.3 Discuss ways that food marketing efforts can influence an individual’s food selections.
1.6 Key Nutrition Concepts
1.6.1 Discuss the importance of the six key nutrition concepts to the study of nutrition.
1.6.2 Compare an empty-calorie food to a nutrient-dense food.
1.6.3 Explain energy density and provide examples of energy-dense food choices.
1.6.4 Describe a dietary supplement according to the Dietary Supplement and Health
Education Act of 1994.
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Overview
In Chapter 1, students will learn about the six classes of nutrients and the general roles of these
nutrients in the human body. Important terms and concepts, including essential nutrients and
phytochemicals, are defined. Students are introduced to the concept of food as fuel and taught
how to estimate the amount of energy in a serving of food based on the quantity of carbohydrate,
fat, protein, and alcohol present in the food. Lifestyle factors that contribute to the leading
causes of death in the United States are discussed, as well as the nutrition-related objectives of
Healthy People 2020. After studying this chapter, students will be able to identify factors that
influence eating habits. In the final section of this chapter, six key concepts to the study of
nutrition are introduced.
Teaching Strategies/Classroom Ideas/Activities
1. Have students read the Case Study in the opening of the chapter and answer the
questions that follow. After they have read the chapter, students should answer the
questions again and compare their answers to the responses provided at the end of the
chapter.
2. Assign Connect® and LearnSmart® activities for Chapter 1.
3. Have students answer the Quiz Yourself questions. Students should save their
responses and answer the questions again, after they have read the chapter.
4. Have students visit Healthy People 2020
(http://www.healthypeople.gov/2020/topicsobjectives2020/default) to access nutrition
and weight status objectives. Students should choose one objective and report on the
goal of the objective. To what extent are Americans reaching this goal?
5. Have students complete the Personal Dietary Analysis in Connect or at the end of
Chapter 1. After completing the dietary analysis, students should share what they
learned about their usual food purchases and consumption practices.
6. Have students determine how well their diets conform to the key concepts of
moderation, variety, and balance.
7. Have students make a list of energy–dense foods that they eat at least once a week.
After making this list, have the students substitute more nutrient-dense foods for the
energy-dense foods they identified.
8. Have students review Figure 1.6 and prepare a family tree that covers at least 3
generations. The “tree” should show year of birth (and death, if applicable) for each
family member, various serious chronic diseases experienced by the relatives, and
their causes of death, if known. As a result of preparing the “tree,” do students think
they are at risk of such diseases? What lifestyle changes (e.g., diet and exercise) can
students adopt to reduce these risks?
9. Assign the Critical Thinking questions and Practice Test at the end of the chapter.
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Extended Chapter Outline
I. The Importance of Nutrition
A. Food is a basic need for human survival and nutrients are the life-sustaining
substances in food.
1. Nutrients are needed for growth, maintenance, and repair of the
body’s cells.
2. Humans have no instinctive drive to select the appropriate mix of
nutrients.
a. Most Americans do not purchase recommended amounts
of certain foods, such as fruits and vegetables.
b. Americans tend to buy more than the recommended
amounts of certain foods, such as red meats and candy.
c. Many serious chronic diseases are associated with certain dietary
practices.
d. People may be able to live longer, healthier lives by improving the
nutritional quality of their diets.
II. The Nutrients
A. The six classes of nutrients are carbohydrates, lipids, proteins, vitamins, minerals, and
water.
1. Figure 1.1 compares the body composition of a healthy man and a healthy
woman.
2. Table 1.1 lists the nutrient classes and their major functions.
3. Cells need the nutrients found in food to carry out their metabolic activities.
4. Metabolism is the total of all chemical processes that occur in living cells.
B. Nutrients are sources of elements that the body needs to carry out activities.
1. Organic refers to compounds that contain carbon; inorganic nutrients are
substances that do not contain carbon.
C. An essential nutrient must be supplied by food.
1. Water is the most essential nutrient.
2. Characteristics of an essential nutrient include the following factors:
a. A specific deficiency disease occurs if the nutrient is missing from the
diet.
b. The abnormal physiological changes caused by the nutrient’s deficiency
are corrected when the missing nutrient is added to the diet.
c. Scientists can explain why the abnormalities occurred when the
substance is missing from the body.
3. Conditionally essential nutrients are nutrients that are normally nonessential
but become essential under certain conditions.
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4. Table 1.3 lists the essential nutrients for humans.
D. Macronutrients are nutrients that the body needs in large amounts daily.
Carbohydrate, fat, and protein are macronutrients. Micronutrients are nutrients that the
body needs very small amounts. Vitamins and minerals are micronutrients.
1. Macronutrients supply energy for cells, whereas micronutrients are not sources
of energy.
2. Although the body requires large amounts of water, this nutrient does not
provide energy and is not usually classified as a macronutrient.
E. Phytochemicals are substances in plants that are not nutrients but may have
healthful benefits. Refer students to Table 1.4 that identifies rich food sources of several
phytochemicals.
III. Food as Fuel
A. A calorie is the amount of heat necessary to raise the temperature of 1 g (1 mL) of
water 1o Celsius (C).
1. A kilocalorie (kcal) or Calorie (C) is the amount of heat energy needed to raise
the temperature of 1000 g (a liter) of water 1o Celsius (C).
2. Appendix I is a food composition table that lists energy and nutrient contents
of many commonly consumed foods and beverages.
B. The calorie content of a food or beverage can be determined through direct
calorimetry. A bomb calorimeter measures the calories in a sample of food (refer to
Figure 1.4).
C. Calculating Food Energy
1. Consumers can calculate the number of kcal in their diets by knowing the
amounts of macronutrients and the nonnutrient alcohol in their foods and
beverages (refer students to Figure 1.5).
IV. Does Diet Matter?
A. Figure 1.6 indicates the 10 leading causes of deaths in the United States and the
approximate percentages of deaths that were attributed to each of them in 2011.
B. In the United States, several of the leading causes of deaths are diet-related (refer
students to Figure 1.6).
C. Risk Factors
1. Chronic diseases are long-term conditions that usually take many years to
develop and generally have complex causes.
2. A risk factor is a characteristic that increases a person’s chances of developing
a chronic disease. Examples of risk factors include genetic background
and family medical history.
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3. Other risk factors that contribute to ill health are unsafe environmental
conditions, such as lack of access to adequate health care and unhealthy
lifestyles.
a. Lifestyle is a routine way of living, including one’s dietary practices and
exercise habits.
b. A person’s lifestyle may increase or reduce his or her chances of
developing many chronic diseases or delay their occurrence.
c. Healthy People 2020 (HP 2020) is a national program that monitors the
health of Americans. HP2020 includes national health promotion and
disease prevention objectives that Americans should meet by 2020. Table
1.5 lists some of the nutrition-related objectives of Healthy People 2020.
V. Factors That Influence Eating Habits
A. Food can have personal meaning and significance, evoke feelings and sensations, and
convey status and ethnicity. Figure 1.7 displays several factors that influence a person’s
usual food selections.
B. Biological and physiological factors that often influence food selections include age,
ability to perceive external sensory information, and internal sensations of hunger and
thirst.
1. Factors that often affect food selections include stage of life (e.g.,
childhood or pregnancy) and health problems.
2. Sensory information includes the taste, odor, and appearance of food.
C. Cognitive and Psychological Factors
1. People learn which foods are acceptable to eat from various factors such as past
experiences, religious teachings, and the media.
2. At times, psychological factors, such as moods and emotional stress, also play
important roles in what an individual chooses to eat.
3. Experiences with food can result in positive or negative associations.
D. Environmental Factors
1. Some environmental factors that play a role in what people eat include income
and location of one’s home.
2. Food manufacturers often develop food packaging and marketing efforts
intended to attract buyers.
VI. Key Nutrition Concepts
A. Concept 1: Most Foods Are Mixtures of Nutrients
1. All foods have some nutritional value, so no food deserves the label of “bad”
or “junk.” (Toxic foods are an exception.) Some foods are healthier to
consume than others.
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2. A nutrient-dense food supplies more vitamins and minerals in relation to total
calories.
3. Energy density is the amount of energy a food provides per given weight of the
food.
a. An energy-dense food has a kilocalorie-to-weight ratio of 4.0 or higher,
according to one rule of thumb.
b. Fatty foods tend to be more energy dense than foods with lower fat or
higher water contents.
c. Figure 1.8 compares two foods that supply similar amounts of calories
but differ in their energy densities.
d. Not all energy-dense foods are empty-calorie foods.
4. Empty-Calorie Foods
a. An empty-calorie food supplies a lot of calories from unhealthy types
of fat, added sugar, and/or alcohol. Such foods generally are not good
sources of vitamins and minerals.
B. Concept 2: Variety, Moderation, and Balance Can Help Ensure a Diet’s Nutritional
Adequacy
1. The human body is designed to obtain the nutrients it needs from a wide variety
of foods.
2. People should also consume each food in reasonable amounts (moderation).
3. By balancing calorie intake with physical activity, people can maintain a
healthy weight (balance).
4. Refer students to Figure 1.10, which compares amounts of energy and certain
nutrients provided by 8-ounce servings of fat-free milk and cola-type, sugarsweetened soft drink.
C. Concept 3: Food Is the Best Source of Nutrients
1. The most reliable and economical way for healthy people to obtain nutrients
and beneficial phytochemicals is to base their diet on a variety of “whole” and
minimally processed foods.
2. Some individuals, such as those with certain chronic diseases or digestive
disorders, need higher amounts of vitamins and other nutrients than those found in
food, and may require supplemental nutrients.
a. A dietary supplement may contain vitamins, minerals, herbs or other
plant products, and/or amino acids.
b. The Dietary Supplement and Health Education Act of 1994 (DSHEA)
is federal legislation that allows manufacturers to classify nutrient
supplements and herbal products as foods.
i. Dietary supplements do not undergo the rigorous testing of
safety and effectiveness that medications must undergo.
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ii. Most commonly dietary supplements are multivitamin/mineral
(MVM) products, including fish oil and glucosamine.
c. The Food and Drug Administration (FDA) does not regulate dietary
supplements as strictly as the agency regulates prescription
medications.
d. For each nutrient, there is a range of safe intake.
i. The physiological dose of a nutrient is the amount that is within
the range of safe intake and enables the body to function
optimally. Refer students to Figure 1.11.
ii. A megadose of a vitamin or mineral is generally at least 10
times the recommended amount of the nutrient.
D. Concept 4: Foods and the Nutrients They Contain Are Not Cure-Alls
1. Diet is only one aspect that influences a person’s health.
2. Functional foods are often manufactured to boost nutrient intakes or help
manage specific health problems.
E. Concept 5: Malnutrition Includes Overnutrition as Well as Undernutrition
1. Malnutrition is a state of health that occurs when the body is improperly
nourished.
a. Chronic overnutrition results in obesity.
b. Obesity is discussed in Chapter 13; undernutrition is discussed in
Chapter 20.
F. Concept 6: Nutrition Is a Dynamic Science
1. Nutrition information constantly changes. Nutrition is not an exact science,
especially when the research involves human subjects. Dietary practices
and recommendations undergo revision as new scientific evidence
becomes available, and the new information is reviewed by other scientists
and accepted.
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