Nutrition Flashcards

-Study of the composition and characteristics of matter and the changes that can occur to it. Matter is anything that takes up space and has mass or weight (on Earth). The air you breathe, this textbook, and even your body consist of chemicals and are forms of matter. "There are chemicals in our food!" This statement may sound frightening, but it is true. Food is matter; therefore, it contains chemicals, some of which are nutrients.

-Nutrient that must be supplied by food
The body can synthesize (make) many nutrients, such as the lipids cholesterol and fat, but about 50 nutrients are dietary essentials. An essential nutrient must be supplied by food, because the body does not synthesize the nutrient or make enough to meet its needs. Water is the most essential nutrient.

-State of health that occurs when a nutrient is missing from the diet
If the nutrient is missing from the diet, a deficiency disease occurs as a result. The deficiency disease is a state of health characterized by certain abnormal physiological changes. Visible or measurable changes are referred to as signs of disease. Disease signs include rashes, failure to grow properly, and elevated blood pressure. Symptoms are subjective complaints of ill health that are difficult to observe and measure, such as dizziness, fatigue, and headache.

When the missing nutrient is added to the diet, the abnormal physiological changes are corrected. As a result, signs and symptoms of the deficiency disorder resolve as normal functioning is restored and the condition is cured.

After scientists identify the nutrient's specific roles in the body, they can explain why the abnormalities occurred when the substance was missing from the diet.

Water, vitamins A, B, Thiamin, Riboflavin, Niacin, Pantothenic acid, biotin, folic acid (folate), B6, B12, Choline, C, D, E and K. Glucose. Minerals include: calcium, chloride, chromium, copper, iodine, iron, magnesium, manganese, molybdenum, phosphorus, selenium, sodium, sulfur, and zinc. Fats that contain linoleic and alpha linoleic acids.

1. most naturally occurring foods are mixtures of nutrients
2. balance and variety ensures nutritional adequacy of the diet
3. there are no good or bad foods
4. enjoy eating food in moderation
5. for each nutrient there is a range of safe intake
6. food is the best source of nutrients and phytochemicals
7. there is no one size fits all
8. foods and the nutrients they contain are not cure-alls
9. malnutrition includes under nutrition as well as over nutrition
10. nutrition is a dynamic science

1. In 2009, an estimated 1 billion people in the world were on the brink of starvation
2. Food shortages may stem from traditional dietary practices, crop failures, civil unrest, and corruption
3. In undernourished children, nutrient deficiencies are responsible for stunted physical growth, impaired physical and intellectual development, blindness and premature death
4. Undernutrition both worsens and is worsened by infectious diseases and parasitic infestations
5. The vast majority of deaths related to undernutrition occur in Africa, Asia, and Latin America

- Pregnancy: 1. Undernutrition during pregnancy increases the risk of premature birth, low birth weight, breathing problems, and infant death
2. An estimated 13 million infants born worldwide have low birth weight; highest incidence in developing countries
- Infancy: Often caused by improper preparation (overdilution) of infant formula in developing countries, which decreases nutritional value and increases risk of contamination by polluted water supplies
2. Exclusive breastfeeding is recommended for infants up to six months of age, with continued breastfeeding in addition to solid foods through the second year of life
3. Diarrheal disease and protein malnutrition result from weaning of infants from breast milk to infant formula in developing countries
- Preschool years
Undernutrition during the preschool years
1. Undernutrition during the first five years of life has negative consequences for the rapid brain growth that occurs during this time, leading to learning disabilities
2. Physical effects include underweight, short stature, and increased risk of death from infectious diseases (e.g., measles)

1. In developed countries, undernutrition is usually not the result of poverty
2. Eating disorders
3. Substance abuse
4. Food insecurity is concern about running out of food or money to buy more food
a. Unemployment, underemployment, excessive medical or housing expenses, fixed incomes contribute to food insecurity
b. Food insecurity affected 15% of U.S. households in 2009
c. Help (especially for children) is available from food pantries and federal food assistance programs

The Supplemental Nutrition Assistance Program (SNAP), formerly known as the Food Stamp Program, aids in purchase of food and garden seeds at authorized outlets
2. Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides nutrition education and vouchers for food for low-income pregnant and breastfeeding women and their preschool children
3. National School Lunch Program provides free or reduced-cost nutritious lunches and afterschool snacks to low-income school-age children
4. School Breakfast Program provides breakfast to low-income school-age children
5. Congregate meal programs and home-delivered meals are available for adults over age 60, regardless of income

1. UNICEF and the World Food Program provide food for undernourished populations
2. Biotechnology uses living things to manufacture improved products and improve food production
a. Genetic modification (genetically modified organisms, or GMOs)
b. GMOs are generally considered safe for human consumption, although some scientists are concerned over potential environmental harm or increased risk of food allergies
c. Maximum capacity for food production may be reached soon due to limited water and land; biotechnology may reduce undernutrition by improving crop yields
3. Food aid is a short-term solution
4. Fortification of locally grown or commonly consumed foods with vitamins and minerals may help to overcome micronutrient deficiencies
5. Population control is important to sustain the earth's resources

28g in an ounce, 454 g in a pound. A kilogram = 1000 g or 2.2 lbs. A person who weighs 130 lbs = 59kg
A raisin weighs 1 gram. If you cut it in 1000 equal pieces each piece weighs 1 milligram. (milli = 1000). 1000 mg equals 1 gram. A normal blood glucose level for a healthy fasting person is 90 milligrams/deciliter (90 mg/dl)

If you wanted to test your body's need for vitamin C, for example, you could avoid consuming foods or vitamin supplements that contain the vitamin. When the amount of vitamin C in your cells became too low for them to function normally, you would develop physical signs of scurvy, the vitamin C deficiency disease. Early in the course of the deficiency, tiny red spots that are actually signs of bleeding under the skin (bruises) would appear where the elastic bands of your clothing applied pressure. When you brushed your teeth, your gums would bleed from the pressure of the toothbrush. If you cut yourself, the wound would heal slowly or not at all. If you started consuming vitamin C-containing foods again, the deficiency signs and symptoms would disappear within a few days as your body recovered. The physiological roles of vitamin C is maintaining a substance in your body that literally holds cells together. This substance is also needed to produce scar tissue for wound healing. When the vitamin is lacking, the tiniest blood vessels in your skin begin to leak blood where the skin is compressed, and even minor cuts have difficulty healing. Thus, vitamin C meets all the required features of an essential nutrient.

Some foods, particularly those from plants, contain substances that are not nutrients, yet they have healthful benefits. Plants make hundreds of phytochemicals (phyto = plant). Caffeine, for example, is a phytochemical naturally made by coffee plants that has a stimulating effect on the body. Many phytochemicals are antioxidants that may reduce risks of heart disease and certain cancers.Not all phytochemicals, however, have beneficial effects on the body; some are toxic (poisonous) or can interfere with the absorption of nutrients. Scientific research that explores the effects of phytochemicals on the body is ongoing.

Many Americans purchase dietary supplements such as vitamin pills and herbal extracts to improve their health. The Dietary Supplement and Health Education Act of 1994 (DSHEA) allows manufacturers to classify nutrient supplements and certain herbal products as foods.4 According to the DSHEA, a dietary supplement is a product (excluding tobacco) that contains a vitamin, a mineral, an herb or other plant product, an amino acid, or a dietary substance that supplements the diet by increasing total intake. According to scientific evidence, some dietary supplements, such as vitamins and certain herbs, can have beneficial effects on health. However, results of scientific testing also indicate that many popular dietary supplements are not helpful and may even be harmful.

A risk factor is a personal characteristic that increases your chances of developing a chronic disease. For example, genetic background or family history is an important risk factor for heart disease. If your father's father had a heart attack before he was 55 years old and your mother is being treated for having a high blood cholesterol level (a risk factor for heart disease), your family history indicates you have a higher-than-average risk of having a heart attack. For many people, however, having a family history of a chronic disease does not mean that they definitely will develop the condition. Other risk factors that contribute to health are age, environmental conditions, psychological factors, access to health care, and lifestyle practices.

Lifestyle is a person's way of living that includes dietary practices, physical activity habits, use of drugs such as tobacco and alcohol, and other typical patterns of behavior. Your lifestyle may increase or reduce your chances of developing a chronic disease or delay its occurrence for years, even decades. Poor diet, cigarette smoking, and excess alcohol consumption, for example, are risk factors that increase the likelihood of heart disease, stroke, and many forms of cancer (see Fig. 1.3). Cigarette smoking is the primary cause of preventable cancer deaths, but dietary habits and physical activity patterns also contribute to the development of certain cancers.6,7 Additionally, poor diet and lack of physical activity can result in obesity, a condition characterized by the accumulation of too much body fat. Obesity is a risk factor for numerous health problems, including heart disease, certain cancers, type 2 diabetes, and hypertension (chronic high blood pressure).

Americans' diets have changed considerably over the past 40 years.1 Today, we eat less red meat and eggs, and more fish and poultry, than in 1970. Our diet supplies more grain and cereal products than in 1970, but refined grain foods, especially white bread, corn chips, and pasta, make up the majority of these products. In general, the more refined a food is, the more processing it has undergone before it reaches your plate, and as a result, the food has lost vitamins, minerals, and other beneficial natural substances. Compared to past years, Americans are eating additional servings of fruit, but many people do not consume enough to meet recommended amounts. Despite the wide variety of fruit available throughout the year, we generally limit our choices to orange juice, bananas, and apples. Today, Americans eat higher amounts of vegetables than in the past, but our choices also tend to lack variety. Almost 50% of the typical American's daily vegetable intake is from iceberg lettuce, French fries, fresh potatoes, potato chips, and canned tomatoes.

Over the past 60 years, our per capita milk and carbonated soft drink consumption patterns have changed dramatically (Table 1.4). In 1947, Americans drank over three and a half times more milk than carbonated soft drinks.8 By 2008-2009, our milk consumption had declined by over 60% and our soft drink consumption had increased by over 300%.8,9 Sugar sweetened soft drinks may contribute to unwanted weight gain10 and replace more nutrient-rich beverages in diets.

Today, the typical American consumes more fat, sugar, and total food energy than in 1970.11 If a person's energy intake is more than needed, especially for physical activity, his or her body fat increases. Nationwide surveys indicate that Americans are fatter than in previous decades. Dietary practices, however, should not receive all the blame for this unhealthy finding; during the same period, we have become increasingly dependent on various labor-saving gadgets and machines that make our lives easier but also reduce the amount of energy we need to expend.

Since the late 1970s, health promotion and disease prevention have been the focus of public health efforts in the United States. A primary focus of such efforts is developing educational programs that can help people prevent chronic and infectious diseases, birth defects, and other serious health problems. In many instances, it is more practical and less expensive to prevent a serious health condition than to treat it.

Healthy People 2010, a report issued in 2000 by the U.S. Department of Health and Human Services (DHHS), included 467 specific national health promotion and disease prevention objectives that were to be met by 2010. The main goals of Healthy People 2010 were to promote healthful lifestyles and reduce preventable death and disability among Americans.

In early 2011, the U.S. Department of Health and Human Services (DHHS) issued Healthy People 2020, a report that includes national health promotion and disease prevention objectives to be met by 2020. The "vision" of Healthy People 2020 is "A society in which all people live long, healthy lives."12 Healthy People 2020 goals encourage Americans to:
Attain higher quality, longer lives that are free of preventable disease, disability, injury, and premature death

Achieve health equity by eliminating disparities to improve the health of all groups

Create social and physical environments that promote good health for all

Promote quality of life, healthy development, and healthy behaviors across all life stages.

Encourage ways for Americans to attain higher quality, longer lives, free of preventable disease, disability, injury and premature death; achieve health equity by eliminating disparities to improve the health of all groups; create social and physical environments that promote good health for all and promote quality of life, healthy development and healthy behaviors across all life stages

There are approximately 2.5 centimeters (cm) per inch. To obtain your approximate height in centimeters, multiply your height in inches by 2.5. For example, a person who is 5′5″ in height (65″) measures about 162.5 cm (65 × 2.5) in length. There are approximately 28 g in an ounce and 454 g in a pound. A kilogram (kilo = 1000) equals 1000 g or about 2.2 pounds. To determine your weight in kilograms (kg), divide your weight in pounds by 2.2. A person who weighs 130 pounds, for example, weighs about 59 kg.

Thus, a kilocalorie (kcal) or Calorie is the heat energy needed to raise the temperature of 1000 g (a liter) of water 1° Celsius (C). A small apple, for example, supplies 40,000 calories or 40 kcal or 40 Calories. If no number of kilocalories is specified, it is appropriate to use "calories." In this textbook, the term "kilocalories" (kcal) is interchangeable with "food energy" or simply "energy."

A gram of carbohydrate and a gram of protein each supply about 4 kcal; a gram of fat provides about 9 kcal (Fig. 1.4). Although alcohol is not a nutrient, it does provide energy; a gram of pure alcohol furnishes 7 kcal. If you know how many grams of carbohydrate, protein, fat, and/or alcohol are in a food, you can estimate the number of kilocalories it provides. For example, if a serving of food contains 10 g of carbohydrate and 5 g of fat, multiply 10 by 4 (the number of kcal each gram of carbohydrate supplies). Then multiply 5 by 9 (the number of kcal each gram of fat supplies). By adding the two values (40 kcal from carbohydrate and 45 kcal from fat), you will determine that this food provides 85 kcal/serving.

For example, an 8-fluid-ounce serving of fat-free milk is about 91% water by weight, but it is an excellent source of protein and supplies carbohydrate, very little fat, and several vitamins and minerals. A 6-ounce plain white potato baked in its skin is 75% water and only about 23% carbohydrate by weight. The baked potato also supplies iron and potassium (minerals) and vitamins C and niacin. About half the weight of a slice of whole-wheat bread is carbohydrate, but slightly over one-third of its weight is water. The bread also contains protein, fat, and some vitamins and minerals.

You may be surprised to learn that many sweet snacks are sources of nutrients other than sugar, a carbohydrate. Although sugar comprises about 44% of the weight of a chocolate with almonds candy bar, over one-third of the sweet snack's energy is from fat. The candy bar also contains small amounts of protein, iron, calcium, vitamin A, and the B-vitamin riboflavin.

Some foods and beverages, such as bacon, candy, pastries, snack chips, and alcoholic or sugar-sweetened drinks, are described as sources of "empty calories." An empty-calorie food contributes a large portion of its energy from solid fat, added sugar, and/or alcohol in relation to its supply of micronutrients. People should limit their intake of empty-calorie foods. Consuming too much food energy in relation to one's needs can result in depositing excess body fat. Furthermore, eating too many empty-calorie foods may displace more nutritious foods from the diet.

Energy density describes the energy value of a food in relation to the food's weight. For example, a chocolate, cake-type frosted doughnut that weighs about 2 ounces provides 242 kcal; 5 medium strawberries also weigh about 2 ounces, but they provide only 19 kcal. You would have to eat nearly 64 of the strawberries to obtain the same amount of food energy that is in the chocolate doughnut. Therefore, the doughnut is an energy-dense food in comparison to the berries. In general, high-fat foods such as doughnuts are energy dense because they are concentrated sources of energy. Most fruits are not energy dense, because they contain far more water than fat. Not all energy-dense foods are empty-calorie foods. Nuts, for example, are high in fat and, therefore, energy dense. However, nuts are also nutrient dense because they contribute protein, vitamins, minerals, and fiber to diets. Most forms of fiber are classified as carbohydrates.

dietary moderation involves obtaining enough nutrients from food to meet one's needs while avoiding excessive amounts and balancing calorie intake with calorie expenditure, primarily by physical activity. This can be accomplished by choosing nutrient-dense foods, limiting serving sizes, and incorporating moderate- to vigorous-intensity physical activities into your daily routine. Although moderation requires planning meals and setting aside time for physical activity daily, it can help you achieve your health and fitness goals. If, for example, you overeat during a meal or snack, you can regain dietary moderation and balance by eating less food and exercising more intensely during the next 24 hours.

The physiological dose of a nutrient is the amount that is within the range of safe intake and enables the body to function optimally. Consuming less than the physiological dose can result in marginal nutritional status. In other words, the person's body has just enough of the nutrient to function adequately, but that amount is not sufficient to overcome the added stress of infection or injury. If a person's nutrient intake falls below the marginal level, the individual is at risk of developing the nutrient's deficiency disease. For example, the recommended amounts of the B-vitamin niacin are 16 mg for men and 14 mg for women.

Most people require physiological amounts of micronutrients. A megadose is generally defined as an amount of a vitamin or mineral that is at least 10 times the recommended amount of the nutrient.14 When taken in high amounts, many vitamins behave like drugs and can produce unpleasant and even toxic side effects. For example, physicians sometimes use megadoses of the B-vitamin niacin to treat high blood cholesterol levels, but such amounts may cause painful facial flushing and liver damage. Megadoses of vitamin C can cause intestinal upsets and diarrhea; consuming extremely high amounts of vitamin A can even be deadly. Minerals have very narrow ranges of safe intakes.

Malnutrition is a state of health that occurs when the body is improperly nourished. Everyone must consume food and water to stay alive, yet despite the abundance and variety of nutritious foods, many Americans consume nutritionally poor diets and suffer from malnutrition as a result. Some people select nutritionally inadequate diets because they lack knowledge about nutritious foods or the importance of nutrition to health. Low-income people, however, are at risk for malnutrition because they have limited financial resources for making wise food purchases. Other people who are at risk of malnutrition include those who have severe eating disorders, are addicted to drugs such as alcohol, or have certain serious medical problems.

Although many people associate malnutrition with undernutrition and starvation, overnutrition, the long-term excess of energy or nutrient intake, is also a form of malnutrition. Overnutrition is often characterized by obesity. You may be surprised to learn that overnutrition is more common in the United States than undernutrition (Fig. 1.10). Obesity is widespread in countries where most people have the financial means to buy food, have an ample food supply, and obtain little exercise.

parts of Africa, Cambodia, and the Philippines, many people eat locusts, especially when the insects are plentiful. Popular ways to cook locusts include removing the wings and legs before frying with seasonings or placing locusts on skewers and roasting them over hot embers. The legs and wings are removed from the grilled insects before they are cooked or eaten. Over 60% of the dry weight of a locust is protein, so the insect is an excellent source of the macronutrient.

Malnutrition is a state of health that results from improper nourishment. Chronic undernutrition occurs when long-term energy and nutrient intakes are insufficient to meet an individual's needs. Hunger, the physiological need for food, usually accompanies undernutrition. Throughout the world, social, environmental, economic, political, and other factors contribute to undernutrition (Fig. 1.11). However, undernutrition is a serious problem, particularly in sub-Saharan Africa and certain regions of Asia, where decades of civil unrest, wars, and the AIDS epidemic have left millions of people impoverished and living in uncertainty. Many developing nations in these regions owe large sums of money to wealthy countries. Having high national debts often causes government leaders to reduce or eliminate basic services, including health care and education programs. Furthermore, undernutrition is common among impoverished people in developing countries where food production and supplies are inadequate.

he world's population is estimated to be over 6.5 billion people. If the present rate of population growth does not slow, an estimated 9 billion people will be living on Earth in 2050.18 Most of the explosive population growth is occurring in developing countries, where economic growth is unable to keep pace with the rapidly increasing number of people.

In 2009, an estimated 1 billion people were on the brink of starvation.19 Regional food shortages can result from traditional dietary practices, crop failures, local warfare, and political instability and corruption. Poverty and undernutrition are commonplace in many developing countries. Impoverished people must also cope with infectious diseases, parasitic infestations, overcrowded and unsafe housing conditions, and polluted water supplies. In developing countries, poor sanitation practices and lack of clean cooking and drinking water cause the majority of all diseases and more than one-third of all deaths

In undernourished children, nutrient deficiencies are responsible for stunted physical growth, delayed physical development, blindness, impaired intellectual development, and premature death. Chronic undernutrition depresses the body's immune functioning, increasing the risk of death from infectious diseases, such as measles, especially in childhood. Each year, maternal and child undernutrition contribute to 3.5 million deaths; nutrition-related factors such as undernutrition and vitamin A deficiency are responsible for 35% of deaths in children under 5 years of age.20 The vast majority of childhood deaths associated with undernutrition occur among poor populations in developing countries, particularly in Africa and Southeast Asia.21

Undernutrition can be very harmful when it occurs during periods of rapid growth, such as pregnancy, infancy, and childhood. Women who are undernourished during pregnancy are more likely to die while giving birth than pregnant women who are adequately nourished. Furthermore, malnourished pregnant women have high risk of giving birth to infants that are born too soon. These babies often suffer from breathing problems and have low birth weights—conditions that increase their risk of dying during their first year of life. Each year, an estimated 13 million low-birth-weight infants are born in the world.22 The vast majority of low-birth-weight infants are born in developing countries.

As explained in Chapter 13, breast milk is the best food for young infants because it is sanitary, is nutritionally adequate, and provides babies with immunity to some infectious diseases. In developing countries, many new mothers do not exclusively breastfeed their babies for more than a few weeks.20 Infant formulas are nutritious substitutes for breast milk, but they are generally more expensive. To extend infant formulas, poor parents in developing countries often add excessive amounts of water. This practice dilutes the nutritional value of the formula and increases the likelihood of contaminating it with disease-causing microbes. In infants, the diarrhea that results from drinking formula mixed with unsanitary water can rapidly cause loss of body water (dehydration) and death.
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Dietitians recommend that infants be breastfed exclusively for the first six months of life. Ideally, babies should continue to receive breast milk in addition to solid foods well into their second year, especially in places where clean water is unavailable. Signs and symptoms of protein malnutrition typically occur soon after impoverished children are weaned abruptly from breast milk and introduced to far less nourishing solid foods.

The brain grows rapidly during the first five years of life. When undernutrition occurs during this period, the effects can be devastating to the child's brain and result in permanent learning disabilities. Additionally, chronically undernourished children do not grow normally and tend to be shorter if they survive to adulthood (Fig. 1.13). In the United States and other developed countries, children are usually well nourished and vaccinated against common childhood diseases such as measles. In poorer nations, however, many children are malnourished and not protected from the virus that causes measles. Measles often is a life-threatening illness for malnourished children because their immune systems do not function normally.

Undernutrition also occurs in wealthy, developed nations such as the United States. In some instances, undernutrition is not due to poverty in these countries. For example, many people suffering from anorexia nervosa and chronic alcoholism are undernourished despite having the financial resources to purchase food. Nevertheless, Americans with low incomes have a higher risk of malnutrition than members of the population who are in higher income categories. In 2009, about 44 million Americans, or about 14.3% of the population, were living at or below the U.S. Department of Health and Human Services poverty guideline. 23 In 2009, this guideline was $21,954 for a family of four. In 2011, the poverty guideline was $22,350 for a family of four.24 Most American households are food secure, which means the people in those households have access to and can purchase sufficient food to lead healthy, active lives. In 2009, food insecurity was reported in almost 15% of all households in the United States.25 Food insecurity describes individuals or families who are concerned about running out of food or not having enough money to buy more food. People who are unemployed, work in low-paying jobs, or have excessive medical and housing expenses often experience food insecurity. Food insecurity may also affect elderly Americans who live on fixed incomes, especially if they are forced to choose between purchasing nutritious food and buying life-extending medications.

The Supplemental Nutrition Assistance Program (SNAP), formerly known as the Food Stamp Program, enables eligible low-income participants to use a special debit card to purchase food and garden seeds at authorized stores. The Women, Infants, and Children program (WIC) provides nutrition education and checks or vouchers to purchase specific foods for low-income pregnant and breastfeeding women and their preschool children who are at "nutritional risk."26 The School Lunch Program provides free or reduced-cost nutritious lunches for eligible low-income students and for after-school snacks at sites that meet certain eligibility requirements (Fig. 1.15). The School Breakfast Program reimburses schools and other nonprofit agencies for the cost of providing a nutritious morning meal to eligible low-income children. The Elderly Nutrition Program provides food assistance for older adults. In many communities, volunteers deliver meals to home-bound people over 60 years of age, regardless of income (Meals on Wheels). Table 1.8 summarizes information about major federally subsidized food programs in the United States.

Reducing hunger through food aid programs is a major goal of the United Nations. The World Food Program and United Nations Children's Fund (UNICEF) are agencies within the United Nations that provide high-quality food for undernourished populations. UNICEF also supports the development and distribution of ready-to-use therapeutic food (RUTF) to treat severe undernutrition among young children in developing countries. Plumpy'nut, for example, is an energy and nutrient-dense paste made from a mixture of peanuts, powdered milk, oil, sugar, vitamins, and minerals. During processing, the paste is placed in foil packets to keep the food clean and make it easy to transport to remote places without refrigeration. According to United Nations officials, RUTFs such as Plumpy'nut are the "best weapon" to fight severe childhood malnutrition.27 In 2010, UNICEF supplied nearly 23,000 tons of RUTFs to feed starving children in developing nations.

Biotechnology involves the use of living things—plants, animals, microbes—to manufacture new products.29 Biotechnology in agriculture has led to the development of crops that supply higher yields, resist pests, or are tolerant of drought conditions. By increasing food production or modifying the nutritional content of foods, biotechnology offers another way of alleviating the world food crisis.

Genetic modification methods, such as genetic engineering, involve scientific methods that alter an animal or plant's hereditary material (genes or DNA). For example, genes that produce a desirable trait are transferred from one organism into the DNA of a second organism, altering its genes. Most of the soybeans and about 40% of the corn grown in the United States are from seeds that were genetically modified (Fig. 1.16). Although these genetically modified organisms or GMOs are used for feeding livestock, many processed foods manufactured for human consumption also contain ingredients from GMOs.

According to Dr. J. Craig Venter, geneticist and founder of the Institute for Genomic Research, the safety of genetically engineered crops destined for human consumption has been tested extensively.30 In 2004, a committee of scientists with the National Research Council reported that there was no documented evidence that genetic engineering resulted in human health problems.29 Some scientists, however, have raised concerns that GMOs introduce new proteins into the food chain, creating the potential for environmental harm. Moreover, certain people who consume foods that contain the new proteins might experience unexpected side effects, such as allergic responses, as a result. Despite these concerns, experts at the U.S. Food and Drug Administration (FDA) think currently approved varieties of genetically engineered foods are safe for human consumption. Nevertheless, more research is needed to determine the long-term safety of GMOs.

In the near future, farmers may find it difficult to sustain a high degree of agricultural productivity as crops and livestock reach their maximum capacity to produce food, particularly as water for irrigation becomes scarce and farmland is used for other purposes, such as housing for the ever-expanding population. Biotechnological advances in agriculture may help reduce the prevalence of undernutrition by increasing livestock production and crop yields in many parts of the world.

Poverty and hunger have always plagued humankind; the causes of poverty and hunger are complex and, therefore, difficult to eliminate. Nevertheless, certain social, political, economic, and agricultural changes can reduce the number of people who are chronically hungry. In the short run, wealthy countries can provide food aid to keep impoverished people from starving to death. Families and small farmers in underdeveloped nations need to learn new and more efficient methods of growing, processing, preserving, and distributing nutritious regional food products. Additionally, governments can support programs that encourage breastfeeding and fortify locally grown or commonly consumed foods with vitamins and minerals that are often deficient in local diets.

In the long run, population control is critical for preserving the earth's resources for future generations. Impoverished parents in poor countries often have many children because they expect only a few to survive and reach adulthood. When people are financially secure, adequately nourished, and well educated, they tend to have fewer, healthier children. Thus, long-term ways to slow population growth include providing well-paying jobs, improving public education, and increasing access to health care services.

A serving of food supplies 20 g carbohydrate, 4 g protein, 10 g fat, and 50 g water. Which of the following statements is true about a serving of the food?
Fat provides the most food energy.
Carbohydrate provides the most food energy.
Water provides the most food energy.
Fat provides about 25% of total calories.

Americans eat less red meat and eggs, and more fish and poultry, than in 1970. The diet supplies more grain and cereal products, but refined grain foods make up the majority of these products. Americans are eating additional servings of fruit, but not enough to meet recommended amounts. Today, Americans eat higher amounts of vegetables than in the past, but choices tend to lack variety. Over the past 60 years, milk consumption declined and carbonated soft drink intake increased dramatically.

a deficiency disease results when the substance is missing from the diet; the deficiency disease is corrected when the missing substance is added to the diet; and scientists can identify the nutrient's specific roles in the body and explain why abnormalities occurred when the substance was missing from the diet.

Poverty and undernutrition are commonplace in many developing countries. Impoverished people must often cope with infectious diseases, parasitic infestations, overcrowded and unsafe housing conditions, and polluted water supplies. In developing countries, poor sanitation practices and lack of clean cooking and drinking water cause the majority of all diseases and more than one-third of all deaths. In undernourished children, nutrient deficiencies are responsible for stunted physical growth, delayed physical development, blindness, impaired intellectual development, and premature death. Chronic undernutrition depresses the body's immune functioning, increasing the risk of death from infectious diseases, such as measles, especially in childhood. The vast majority of childhood deaths associated with undernutrition occur among poor populations in developing countries, particularly in Africa, Asia, and Latin America. When undernutrition occurs during the first five years of life, the effects can be devastating to the child's brain and result in permanent learning disabilities. Additionally, chronically undernourished children do not grow normally and tend to be shorter if they survive to adulthood.

A group of scientists conducts a scientific study to investigate dietary factors that influence the development of obesity. Which of the following activities is not likely to be a component of their research efforts?
Collecting data and analyzing results
correct Posting findings at the main researcher's Internet web site
Submitting an article describing the study to a peer-reviewed journal
Making observations and formulating a hypothesis

Researchers at a major American university plan a scientific study to investigate lifestyle factors that contribute to heart disease. Which of the following activities is likely to be a component of their research efforts?
Obtaining FDA and FTC approval to conduct research on human subjects
correct Submitting an article describing the study to a peer-reviewed journal
Posting significant findings at the main researcher's Internet web site
None of these is correct.