Food and nutrition assignment

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1 Learning Outcomes After reading this chapter, you will be able to:

1.1 Discuss the factors that drive our food choices.

1.2 Define the term nutrition and characterize nutrients.

1.3 Explain the primary roles of the six classes of nutrients found in food.

1.4 Describe the best approach to meeting your nutritional needs.

1.5 Summarize three ways in which diet influences health.

1.6 Summarize the ABCD method used to assess the nutrient status of individuals and populations.

1.7 Discuss the current nutritional state of the average American diet.

1.8 Describe the scientific method that leads to reliable and accurate nutrition information.

1.9 Explain how to identify reliable nutrition infor- mation and how to recognize misinformation.

True or False? 1. Food choices are driven primarily by flavor. T/F 2. Nutrition is the study of dietary

supplements. T/F 3. Carbohydrates provide our main source of energy. T/F 4. Alcohol is a nutrient. T/F 5. Taking a dietary supplement is the only way to meet your nutrient needs. T/F 6. The most effective method of nutritional assessment is to ask clients to write down what they’ve eaten in the last 24 hours. T/F 7. About 25 percent of all Americans are obese. T/F 8. Eliminating all fat from the diet will

reduce your risk of developing heart disease. T/F 9. Cancer is the leading cause of death in the United States. T/F

10. You can get good nutrition advice from anyone who calls him- or herself a nutritionist. T/F See page 36 for the answers.

What Is Nutrition?

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4 Chapter 1 | What Is Nutrition?

What Drives Our Food Choices? LO 1.1 Discuss the factors that drive our food choices.

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? Do you enjoy some foods and eat them often, while avoiding others with a vengeance? You obviously need food to survive, but beyond your basic instinct to eat are many other factors that affect your food choices. These factors include taste and enjoyment; culture and environment; social life and trends; nutrition knowledge; advertising; time, convenience, and cost; and habits and emotions (Figure 1.1).

Taste and Enjoyment Research confirms that when it comes to making food choices, taste is the most important consideration.2,3 This shouldn’t be too much of a surprise, considering there are more than 10,000 taste buds in the mouth. These taste buds tell you that chocolate cheesecake is sweet, fresh lemon juice is sour, and a pretzel is salty. Our preferences for sweet, salty, or creamy foods may be inf luenced by our genes4 and may change as we age.5

We have a taste for fat, which may also be genetically linked.6 When fat is combined with sugar, such as in a sugar-laden doughnut, our preference for that food is even stronger.7

Texture also affects our likelihood of enjoying foods. We enjoy a f laky piecrust 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 people’s preferences for sweetness, high fat, and specific textures begin early in life and this makes them resistant to change.9▲ Figure 1.1 Many Factors Influence Your Food Choices

Food Choices

Advertising Social reasons

Convenience

Emotions

Time

Habits

Culture

Nutrients

Cost

Taste

TrendsNutrition knowledge

During the course of a 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 size plate to use.1 You make these decisions for reasons you may not even be aware of. If your dietary advice comes from media sound

bites, you may receive conflicting information. Last week’s news flash announced that eating more pro-

tein would help you fight a bulging waist. Yesterday’s headline boldly announced that limiting sugary

drinks was the key. This morning, the TV news lead was a health report on the weight-loss benefits of

consuming more dietary fiber.

It can be frustrating when nutrition news seems to change daily, but the research behind this barrage

of news illustrates the progress nutrition scientists are making toward understanding what we eat and

how it affects our health. Today’s research validates what nutrition professionals have known for decades:

Nutrition plays an invaluable role in your health.

In addition to exploring the factors that affect food choice, this chapter introduces you to the study

of nutrition. Let’s begin with the basic concepts of why and what you eat, why a healthy diet is important

to your well-being, and how you can identify credible sources of nutrition information.

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What Drives Our Food Choices? 5

Culture and Environment Enjoying food is not just a physiological sensation. Other factors, such as our culture and the environment, also play a role in which foods we eat.10 If you were a student in Mexico, you may regularly feast on corn tortillas and tamales, as corn is a staple of Mexican cuisines. In India, meals commonly include lentils with rice and vegetables, whereas Native Americans often enjoy stews of mutton (sheep), corn, vegetables, and berries. And, in Asian countries, rice likely would be front and center on your plate.

The environment in which its people live significantly influences a culture’s cuisine. This includes the climate and soil conditions as well as the native plants and animals and the distance people live from rivers, lakes, or the ocean. Foods that are available and acces- sible are more likely to be regularly consumed than foods that are scarce. For example, native Alaskans feast on fish because it is plentiful, but eat less fresh produce, which is difficult to grow locally. For most Americans today, global food distribution networks have made eating only locally available foods less of an issue than in the past; however, the tendency persists for some food items.

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 that are visible—has a strong influence on what and how much we consume. We eat more food when the serving plates are larger and drink less when beverages are served in taller glasses. Environmental cues also affect eating patterns. You are more likely to linger over a meal when the light is dimmed,11 or quickly finish your meal when you are standing rather than sitting. Physical cues, such as a friend’s empty appetizer plate covered with disposed-of cocktail sticks, may signal you to eat more of your appetizer.

Social Life and Trends Every year on the fourth Thursday in November, approximately 48 million turkeys are consumed when Americans gather with family and friends to celebrate Thanksgiving.12 A person is likely to eat more on Thanksgiving than on any other Thursday, and this is partly because of the number of people eating with them. Eating dinner with others has been shown to increase the size of the meal by over 40 percent, and the more people present at the meal, the more you’ll eat.13

Eating is an important way to bond with others. Sharing a meal with family or friends stimulates conversation, creates traditions, and expands our food experiences. Although eat- ing a quick meal in the campus cafeteria may not provide you the most healthy food options, 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 on any other day of the year.14 Movie theater owners bank on their patrons buying popcorn, candy, and beverages at the concession stand before heading in to watch the film.15

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, vegetables 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 if the food is labeled “organic.” In 2013 alone, Americans spent more than $35 billion on organic foods.16 Millennials (people born between about 1980 and 2000) who are parents are the biggest group of consumers buying organic foods.

Roughly one in three Americans is of Hispanic, Native American, Asian, or African descent. Cultural food preferences often influence food choices.

Eating junk food while watching sports or attending a sporting event sometimes seems like an American way of life.

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6 Chapter 1 | What Is Nutrition?

Food sustainability and food waste are also topics that are on the radar of restaurant patrons and shoppers, who may choose vegetarian meals or smaller portions out of concerns for the environment. Supermarkets provide dozens of choices in flavored and enhanced bottled teas and waters, which are trendy beverages among college students. As food manufacturers pour more money into research and development, who knows what tomorrow’s trendy foods will be?

Nutrition Knowledge Individuals may choose certain foods they associate with good health or avoid other foods they associate with poor health. For example, many Americans consume vegetables, fruits, and whole

grains because they perceive them as healthy choices that can help them control their blood pressure or reduce their risk of colon cancer.17 At the same time, many Americans worry about fried foods causing heart disease.

When it comes to weight management, some consumers believe that specific dietary components are the culprits behind weight gain. While 3 in 10 consumers believe that overeating any type of food will cause weight gain, one in four believe that sugar is more likely to cause you to pack on the pounds.18

The more aware you are of the effects of food choices on health, the more likely you are to make an effort to improve those choices. If you believe that choosing low-sodium foods will decrease your blood pressure or that eating yogurt with active cultures will improve your digestion, you are more likely to choose these foods. Many consumers are label-reading in the supermarket, checking the expiration date, Nutrition Facts panel, and ingredients list before buying a food product.19

Advertising The food and beverage industry spends over $136 million annually on advertising.20 Food companies spend these large sums on advertising for one reason: It works, especially on young people. American children view an estimated 30 hours of food commercials on the television annually, and more than half of these advertisements are for unhealthy foods.21

In contrast, commercials for fruits and vegetables are rare, which is unfortunate because healthy foods can be successfully marketed. The Fruit and Vegetable (FNV) campaign, the brainchild of the Partnership for a Healthier America (PHA), a nonprofit organization working with public, private, and nonprofit leaders to develop strategies to end childhood obesity, knows that celebrity marketing to kids is powerful. They recruited influential actors and athletes, all pro bono, to get kids to chow down more produce. Their research showed that 70 percent of individuals who were aware of FNV stated that they purchased and ate more fruits and vegetables after seeing or hearing about the campaign.22

Time, Convenience, and Cost When it comes to making a meal, time is often at a premium. A recent survey reported that close to 60 percent of Millennials spend as little as 15 minutes cooking dinner during the week.23 Consequently, supermarkets are now offering more prepared and partially 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 rotisserie, cooked and stuffed with bread crumbs or grilled with teriyaki sauce. Rice or pasta side dishes and cooked vegetables are also available to complete the meal.

The USDA certifies that foods labeled “organic” are grown without the use of toxic and persistent pesticides or fertilizers.

Rates of fruit and vegetable consumption increased among consumers exposed to the FNV advertising campaign.

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What Is Nutrition? 7

Convenience has also become more of a factor in food selection. Foods that are easily accessible to you are more likely to be eaten. 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 29,000 coffee shops across the United States.24

For reasons related to both time and convenience, people eat out more often today than they did a few decades ago. In the 1970s, Americans spent less of their household budget on eating out, compared with today.25 Because cost is often an issue when con- sidering 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-calorie 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.26

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. More Americans, especially urban Millennials, are opting for boxes of fresh fruits and vegetables or meal kits delivered directly to their door. They may eat home-cooked meals more often because of these services.27

Researchers have found that lowering the cost of fresh fruits and vegetables improves the consumption of these nutritious foods.28 This suggests that price reductions are an effective strategy to increase the purchase of more-healthful foods.

Habits and Emotions Your daily routine and habits often affect both when you eat and what you eat. For exam- ple, if you routinely start your day with a bowl of cereal, you’re not alone. Ready-to-eat cereals are the number-one breakfast food choice among Americans.29 Many individuals habitually snack when watching television or sitting at the computer.30

For some individuals, emotions can sometimes drive food choice: feeling happy or sad can trigger eating. In some cases, appetite is suppressed during periods of sadness or depression; in others, food is used as an emotional crutch during times of stress, depres- sion, or joy.

Although brown rice is a healthy whole-grain addition to any meal, it generally takes almost an hour to cook. For time-strapped consumers, food manufacturers have developed brown rice that cooks in 10 minutes and a precooked, microwavable variety that reheats in less than 2 minutes.

LO 1.1: THE TAKE-HOME MESSAGE Taste and enjoyment are the primary rea- sons people prefer certain foods. A food’s availability makes it more easily become part of a culture, and many foods can be regularly eaten out of habit. Advertising, food trends, limited time, convenience, emotions, and the percep- tion that foods are healthy or unhealthy also influence food choices.

What Is Nutrition? LO 1.2 Define the term nutrition and characterize nutrients.

The science of nutrition is the study of food and the nutrients we need to sustain life and reproduce. It examines the way food nourishes the body and affects health. Since its incep- tion, the science of nutrition has explored how food is digested, absorbed, 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. 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.

nutrition Science that studies how nutrients and other components of foods nourish the body and affect body functions and overall health.

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8 Chapter 1 | What Is Nutrition?

Nutrients Are Essential Compounds in Food The body is one large organism made up of millions of cells that grow, age, reproduce, 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 also provide the energy we need to perform all body functions and processes, from maintaining heartbeat to playing tennis.

There are six categories of nutrients found in foods and in the body: carbohydrates, lipids (fats), protein, vitamins, minerals, and water. Foods also often contain beneficial non-nutrient compounds, such as phytochemicals or zoochemicals, and nondigestible fiber, as well as chemicals added by food manufacturers to enhance color, flavor, or tex- ture or extend shelf-life.

Plant foods are made up of about 10 percent carbohydrates, fats, proteins, vitamins, and minerals (Figure 1.2). The rest is typically water, and plant foods contain more water (about 90 percent) than do animal foods (about 70 percent). Animal foods are composed of about 30 percent protein, lipids, vitamins, and minerals. One unique quality of animal foods, with the exception of dairy products, is that they do not contain any carbohydrates by the time we consume them.

A healthy human body is about 60 percent water. The other 40 percent is made up of protein and fat, as well as a small amount of stored carbohydrates, minerals in bone, and small amounts of vitamins. Thus, the old saying is true that 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.

In general, nutrients are essential—they must come from foods because either they cannot be made in the body at all, or they cannot be made in sufficient amounts to meet the body’s needs. The body can make a few nonessential nutrients in sufficient quanti- ties. An example is vitamin D, which is synthesized in the skin upon exposure to sunlight. Under some circumstances, nonessential nutrients can become essential. We refer to these nutrients as conditionally essential. If you are not exposed to enough sunlight, you will not be able to synthesize an adequate amount of vitamin D. You must then obtain vitamin D from foods and/or supplements.

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 1.3).

Minerals are the least complex of the nutrients. From calcium to zinc, each mineral is an individual element, and its atoms are exactly the same whether found in food or in the body. For instance, the structure of zinc found in lean meats and nuts is the same as that found in a cell membrane or a hair follicle. Minerals are inorganic because, as individual elements, they do not contain carbon. Water, a three-atom molecule composed of hydrogen and oxygen, is also inorganic. The Chemistry Boost will help you visualize elements and molecules.

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. It also provides a source of heat. The body derives chemical energy from certain nutrients in foods, which store energy in their chemical

nutrients Compounds in foods that sustain body processes. There are six classes of nutrients: carbohydrates, fats (lipids), proteins, vitamins, minerals, and water.

essential nutrients Nutrients that must be consumed from foods because they cannot be made in the body in sufficient quantities to meet its needs and support health.

▲ Figure 1.2 Nutrients in Foods and in the Body Water is the most abundant nutrient found in foods and in the body. Carbohydrates, fats, protein, vitamins, and minerals make up the rest. Note that foods also contain non-nutritive compounds, such as phytochemicals and fiber.

Minerals

Minerals

Vitamins

Vitamins

Minerals Vitamins

Carbohydrates

Protein

Fat

Water

Human body

Protein

Fat

Water

Protein

Water

Carbohydrates

Chicken breast

59%

20%

17%

Broccoli (raw)

22%

74%

7%

89%

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What Is Nutrition? 9

bonds. During digestion and metabolism, the bonds are broken and the energy is released. This chemical energy released when the foods are digested can be converted into adenosine triphosphate (ATP), a form of energy the body can use. Carbohydrates, lipids (fats), and proteins are defined as the energy-yielding nutrients because they contribute energy to the body. Alcohol, although not a nutrient, also provides energy.