Food and Nutrient Delivery

Dietary Reference Intakes

American standards for nutrient requirements have been the recommended dietary allowances (RDAs) established by the FNB of the IOM. They were first published in 1941 and most recently revised between 1997 and 2002. Each revision incorporates the most recent research findings. In 1993 the FNB developed a framework for the development of nutrient recommendations, called dietary reference intakes (DRI). Nutrition and health professionals should always use updated food composition databases and tables and inquire whether data used in computerized nutrient analysis programs have been revised to include the most up-to-date information. An interactive DRI calculator is available at http://fnic.nal.usda.gov/interactiveDRI/.

Food and Nutrient Intake Data

Information about the diet and nutritional status of Americans and the relationship between diet and health is collected by 22 federal agencies. This effort is coordinated by the USDA and USDHHS through the National Nutrition Monitoring and Related Research Program, (See Chapter 10). Overall, analysis of the American diet shows that the population is slowly changing eating patterns and adopting more healthy diets. Intake of total fat, saturated fatty acids, and cholesterol has decreased in some segments of the population; servings of fruits and vegetables have risen to four per day. Hospitals have even taken on the challenge for healthier food intake (see Focus On: The “Healthy Food In Health Care” Pledge).

Unfortunately, gaps still exist between actual consumption and government recommendations in certain population subgroups. Nutrition-related health measurements indicate that overweight and obesity are increasing from lack of physical activity. Hypertension remains a major public health problem in middle-age and older adults and in non-Hispanic blacks in whom it increases the risk of stroke and coronary heart disease. Osteoporosis develops more often among non-Hispanic whites than non-Hispanic blacks. Finally, in spite of available choices, many Americans experience food insecurity, meaning that they lack access to adequate and safe food for an active, healthy life. Table 12-2 provides a list of food components and public health concerns related to those components.

Healthy Eating Index

The Center for Nutrition Policy and Promotion of the USDA releases the Healthy Eating Index (HEI) to measure how well people’s diets conform to recommended healthy eating patterns. The index provides a picture of foods people are eating, the amount of variety in their diets, and compliance with specific recommendations in the Dietary Guidelines for Americans (DGA). The HEI is designed to assess and monitor the dietary status of Americans by evaluating 10 components, each representing different aspects of a healthy diet. The dietary components used in the evaluation include grains, vegetables, fruits, milk, meat, total fat, saturated fat, cholesterol, sodium, and variety. Data from the HEI over time show that Americans are reducing total and saturated fat and eating a wider variety of foods. The 2005 report suggests that milk intake is still low (Guenther et al., 2008). The overall HEI score ranges from 0 to 100. Interestingly, women generally have scores higher than men, and toddlers have the highest scores.

Nutrition Monitoring Report

At the request of the USDHHS and USDA, the Expert Panel on Nutrition Monitoring was established by the Life Sciences Research Office of the Federation of American Societies for Experimental Biology to review the dietary and nutritional status of the American population. In general, the committee concluded that the food supply in the United States is abundant, although some people may not receive enough nutrients for various reasons. Nutrient intakes are most likely to be low in persons living below the poverty level. Intakes of nutrients reported to be low in the general population are even lower in the poverty group. Chapter 10 describes this report more fully.

Current Dietary Guidance

In 1969 President Nixon convened the White House Conference on Nutrition and Health (AJCN, 1969). Increased attention was being given to prevention of hunger and disease. The development of dietary guidelines in the United States is discussed in Chapter 10. Guidelines directed toward prevention of a particular disease, such as those from the National Cancer Institute; the American Diabetes Association; the American Heart Association; and the National Heart, Lung, and Blood Institute’s cholesterol education guidelines, contain recommendations unique to particular conditions. The American Dietetic Association supports a total diet approach, in which the overall pattern of food eaten, consumed in moderation with appropriate portion sizes and combined with regular physical activity, is key. Various guidelines that can be used by health counselors throughout the developed world are summarized in Box 12-1.

Implementing the Guidelines

The task of planning nutritious meals centers on including the essential nutrients in sufficient amounts as outlined in the newest DRIs, in addition to appropriate amounts of energy, protein, carbohydrate (including fiber and sugars), fat (especially saturated and trans-fats), cholesterol, and salt. Suggestions are included to help people meet the specifics of the recommendations. When specific numeric recommendations differ, they are presented as ranges.

To help people select an eating pattern that achieves specific health promotion or disease prevention objectives, nutritionists should assist individuals in making food choices (e.g., to reduce fat, to increase fiber). Although numerous federal agencies are involved in the issuance of dietary guidance, the USDA and USDHHS lead the effort. The Dietary Guidelines for Americans (DGA) were first published in 1980 and are revised every five years; the most recent guidelines were released in 2010 (Box 12-2). The DGA are designed to motivate consumers to change their eating and activity patterns by providing them with positive, simple messages. Using consumer research, the DGA develop messages that expand the influence of the dietary guidelines to encourage consumers to adopt them and ultimately change their behaviors. The messages reach out to consumers’ motivations, individual needs, and life goals, and can be used in education, counseling, and communications initiatives (USDA, 2005).

The MyPlate Food Guidance System, shown in Figure 12-1, replaces the MyPyramid and offers a guide for daily food choices and portions. Consumers can use chooseMyPlate.gov as a resource.

For comparison, see the Eating Well with Canada’s Food Guide as shown in Clinical Insight: Nutrition Recommendations for Canadians and Figure 12-2.

Mandatory Nutrition Labeling

As a result of the NLEA, nutrition labels must appear on most foods except products that provide few nutrients (such as coffee and spices), restaurant foods, and ready-to-eat foods prepared on site, such as supermarket bakery and deli items. Providing nutrition information on many raw foods is voluntary. However, the FDA and USDA have called for a voluntary point-of-purchase program in which nutrition information is available in most supermarkets. Nutrition information is provided through brochures or point-of-purchase posters for the 20 most popular fruits, vegetables, and fresh fish and the 45 major cuts of fresh meat and poultry.

Nutrition information for foods purchased in restaurants is widely available at the point of purchase or from Internet sites or toll-free numbers. New legislation may require chains with 20 or more locations to disclose on their menus or menu board the number of calories per menu item, with additional nutrition information including total calories and calories from fat, and amounts of fat, saturated fat, cholesterol, sodium, total carbohydrates, complex carbohydrates, sugars, dietary fiber, and protein available upon request.

Ready-to-eat unpackaged foods in delicatessens or supermarkets may provide nutrition information voluntarily. However, if nutrition claims are made, nutrition labeling is required at the point of purchase. If a food makes the claim of being organic, it also must meet certain criteria and labeling requirements.

Standardized Serving Sizes on Food Label

Serving sizes of products are set by the government based on reference amounts commonly consumed. For example, a serving of milk is 8 oz, and a serving of salad dressing is 2 tbsp. Standardized serving sizes make it easier for consumers to compare the nutrient contents of similar products (Figure 12-3).

Nutrition Facts Label

The nutrition facts label on a food product provides information on its per-serving calories and calories from fat. The label must list the amount (in grams) of total fat, saturated fat, trans fat, cholesterol, sodium, total carbohydrate, dietary fiber, sugar, and protein. For most of these nutrients the label also shows the percentage of the daily value (DV) supplied by a serving, showing how a product fits into an overall diet by comparing its nutrient content with recommended intakes of those nutrients. DVs are not recommended intakes for individuals; they are simply reference points to provide some perspective on daily nutrient needs. DVs are based on a 2000-kcal diet. For example, individuals who consume diets supplying more or fewer calories can still use the DVs as a rough guide to ensure that they are getting adequate amounts of vitamin C but not too much saturated fat.

The DVs exist for nutrients for which RDAs already exist (in which case they are known as reference daily intakes [RDIs]) (Table 12-3) and for which no RDAs exist (in which case they are known as daily reference values [DRVs] [Table 12-4]). However, food labels use only the term daily value. RDIs provide a large margin of safety; in general, the RDI for a nutrient is greater than the RDA for a specific age-group. The term RDI replaces the term U.S. RDAs used on previous food labels. The previously mentioned nutrients must be listed on the food label.

As new DRIs are developed in various categories, labeling laws are updated. Figure 12-4 shows a sample nutrition facts label, and Box 12-3 provides tips for reading and understanding food labels. The FDA has a helpful website to assist consumers with reading labels (http://www.fda.gov/Food/LabelingNutrition/ConsumerInformation/UCM078889.htm).

Nutrient Content Claims

Nutrient content terms such as reduced sodium, fat free, low calorie, and healthy must now meet government definitions that apply to all foods (Box 12-4). For example, lean refers to a serving of meat, poultry, seafood, or game meat with less than 10 g of fat, less than 4 g of saturated fat, and less than 95 mg of cholesterol per serving or per 100 g. Extra lean meat or poultry contains less than 5 g of fat, less than 2 g of saturated fat, and the same cholesterol content as lean, per serving, or per 100 g of product.

Health Claims

A health claim is allowed only on appropriate food products that meet specified standards. The government requires that health claims be worded in ways that are not misleading (e.g., the claim cannot imply that the food product itself helps prevent disease). Health claims cannot appear on foods that supply more than 20% of the DV for fat, saturated fat, cholesterol, and sodium. The following is an example of a health claim for dietary fiber and cancer: “Low-fat diets rich in fiber-containing grain products, fruits, and vegetables may reduce the risk of some types of cancer, a disease associated with many factors.” Box 12-5 lists health claims that manufacturers can use to describe food-disease relationships.

Vegetarian Diet Patterns

Vegetarian diets are popular. Those who choose them may be motivated by philosophic, religious, or ecologic concerns, or by a desire to have a healthier lifestyle. Considerable evidence attests to the health benefits of a vegetarian diet. Studies of Seventh-Day Adventists indicate that the diet results in lower rates of type 2 diabetes, breast and colon cancer, and cardiovascular and gallbladder disease.

Of the millions of Americans who call themselves vegetarians, many eliminate “red” meats but eat fish, poultry, and dairy products. A lactovegetarian does not eat meat, fish, poultry, or eggs, but does consume milk, cheese, and other dairy products. A lactoovovegetarian also consumes eggs. A vegan does not eat any food of animal origin. The vegan diet is the only vegetarian diet that has any real risk of providing inadequate nutrition, but this risk can be avoided by careful planning (American Dietetic Association [ADA], 2009). A new type of semivegetarian is known as a flexitarian. Flexitarians generally adhere to a vegetarian diet for the purpose of good health and do not follow a specific ideology. They view an occasional meat meal as acceptable.

Vegetarian diets tend to be lower in iron than omnivorous diets, although the nonheme iron in fruits, vegetables, and unrefined cereals is usually accompanied either in the food or in the meal by large amounts of ascorbic acid that aids in iron assimilation. Vegetarians do not have a greater risk of iron deficiency than those who are not vegetarians (ADA, 2009). Vegetarians who consume no dairy products may have low calcium intakes, and vitamin D intakes may be inadequate among those in northern latitudes where there is less exposure to sunshine. The calcium in some vegetables is inactivated by the presence of oxalates. Although phytates in unrefined cereals also can inactivate calcium, this is not a problem for Western vegetarians, whose diets tend to be based more on fruits and vegetables than on the unrefined cereals of Middle Eastern cultures. Long-term vegans may develop megaloblastic anemia because of a deficiency of vitamin B₁₂, found only in foods of animal origin. The high levels of folate in vegan diets may mask the neurologic damage of a vitamin B₁₂ deficiency. Vegans should have a reliable source of vitamin B₁₂ such as fortified breakfast cereals, soy beverages, or a supplement. Although most vegetarians meet or exceed the requirements for protein, their diets tend to be lower in protein than those of omnivores. This lower intake may help vegetarians retain more calcium from their diets. Furthermore, lower protein intake usually results in lower dietary fat because many high-protein animal products are also rich in fat (ADA, 2009).

Well-planned vegetarian diets are safe for infants, children, and adolescents and can meet all of their nutritional requirements for growth. They are also adequate for pregnant and lactating females. The key is that the diets be well planned. Vegetarians should pay special attention to ensure that they get adequate calcium, iron, zinc, and vitamins B₁₂ and D. Calculated combinations of complementary protein sources is not necessary, especially if protein sources are reasonably varied. Table 12-5 highlights many of the phytochemicals and functional components rich in many vegetable-based diets. A useful website on vegetarian meal planning is available at http://www.eatright.org/ through the American Dietetic Association. See also Focus On: The “Healthy Food In Health Care” Pledge earlier in the chapter.

Religion and Food

Dietary practices have been a component of religious practice for all of recorded history. Some religions forbid the eating of certain foods and beverages; others restrict foods and drinks during holy days. Specific dietary rituals may be assigned to members with designated authority or with special spiritual power (e.g., medicine men, priests). Sometimes dietary rituals or restrictions are observed based on gender. Dietary and food preparation practices (e.g., halal and kosher meat preparation) can be associated with rituals of faith.

Fasting is practiced by many religions. It has been identified as a mechanism that allows one to improve one’s body, to earn approval (as with Allah or Buddha), or to understand and appreciate the sufferings of others. Attention to specific eating behaviors such as overeating, use of alcoholic or stimulant-containing beverages, and vegetarianism are also considered by some religions. Before planning menus for members of any religious group, it is important to gain an understanding of some traditions or dietary practices (Table 12-6). In all cases, discussing the personal dietary preferences of an individual is imperative (Kittler and Sucher, 2008).

American Dietetic Association

http://www.eatright.org

Center for Nutrition Policy and Promotion, U.S. Department of Agriculture

http://www.usda.gov/cnpp/

Centers for Disease Control—Health Literacy

http://www.cdc.gov/healthmarketing/healthliteracy/training/page5711.html

Cost of Food at Home

http://www.cnpp.usda.gov/USDAFoodCost-Home.htm

Dietary Guidelines for Americans

http://www.health.gov/DietaryGuidelines

Eat Smart, Play Hard

http://www.fns.usda.gov/eatsmartplayhardkids/

Ethnic Food Guides

http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=3&_tax_subject=256&topic_id=1348&level3_id=5732

Food and Drug Administration, Center for Food Safety and Applied Nutrition

http://www.cfsan.fda.gov

Food and Nutrition Information Center, National Agricultural Library, U.S. Department of Agriculture

http://www.nal.usda.gov/fnic/

Health Canada

http://www.hc-sc.gc.ca/fn-an/index_e.html

Healthy Eating Index

http://www.cnpp.usda.gov/HealthyEatingIndex.htm

Institute of Medicine, National Academy of Sciences

http://www.iom.edu/

International Food Information Council

http://ific.org

MyPlate Food Guidance System

http://www.chooseMyPlate.gov/

National Center for Health Statistics

http://www.cdc.gov/nchs/nhanes.htm

Nutrition.gov (U.S. government nutrition site)

http://www.nutrition.gov

U.S. Department of Agriculture

http://www.usda.gov

American Dietetic Association (ADA). Position of the American Dietetic Association: vegetarian diets. J Am Diet Assoc. 2009;109:1266.

American Journal of Clinical Nutrition. White House Conference on Food, Nutrition and Health. AJCN. 1969;11:1543.

Betancourt, JR, Green, AR. Commentary: linking cultural competence training to improved health outcomes: perspectives from the field. Acad Med. 2010;85:583.

Diabetes Care and Education Dietetic Practice Group. Goody CM, Drago L, eds. Cultural food practices. Chicago: American Dietetic Association, 2010.

Guenther, P, et al. Healthy eating index. J Am Diet Assoc. 2008;108:1854–1864.

Health Canada. Eating well with Canada’s food guide. Her Majesty the Queen in Right of Canada, represented by the Minister of Healthy Canada, 2007. Accessed 18 January 2010 from www.hc-sc.gc.ca/fn-an/food-guide-aliment.

Institute of Medicine (IOM), Food and Nutrition Board, Consensus Report: Dietary reference intakes: water, potassium, sodium, chloride, and sulfate. Accessed 11 March, 2011 at http://www.iom.edu/reports/2004/dietary-reference-intakes-water-potassium-sodium-chloride-and-sulfate.aspx.

Kittler, PG, Sucher, KP. Food and culture, ed 5. Belmont, CA: Wadsworth/Cengage Learning; 2008.

Pollan, M. The omnivore’s dilemma: a natural history of four meals. New York: Penguin; 2006.

U.S. Department of Agriculture, Center for Nutrition Policy and Promotion. Healthy eating index 2005. Accessed 16 April 2007 from www.cnpp.usda.gov.