lder adults. Together with physical activity, a highquality diet that does not provide excess calories should enhance the health of most individuals.
Poor diet and physical inactivity, resulting in an energy imbalance (more calories consumed than expended), are the most important factors contributing to the increase in overweight and obesity in this country. Moreover, overweight and obesity are major risk factors for certain chronic diseases such as diabetes. In 1999–2002, 65 percent of
U.S. adults were overweight, an increase from 56 percent in 1988–1994. Data from 1999–2002 also showed that 30 percent of adults were obese, an increase from 23 percent in an earlier survey. Dramatic increases in the prevalence of overweight have occurred in children and adolescents of both sexes, with approximately 16 percent of children and adolescents aged 6 to 19 years considered to be overweight (1999–2002). 3 In order to reverse this trend, many Americans need to consume fewer calories, be more active, and make wiser choices within and among food groups. The Dietary Guidelines provides a framework to promote healthier lifestyles (see ch. 3).
Given the importance of a balanced diet to health, the intent of the Dietary Guidelines is to summarize and synthesize knowledge regarding individual nutrients and
3 Hedley AA, Ogden CL, Johnson CL, Carroll MD, Curtin LR, Flegal KM. Prevalence of overweight and obesity among U.S. children, adolescents, and adults, 19992002. Journal of the American Medical Association (JAMA) 291(23):28472850, 2004.
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food components into recommendations for an overall pattern of eating that can be adopted by the general public. These patterns are exemplified by the USDA Food Guide and the DASH Eating Plan (see ch. 2 and app. A). The Dietary Guidelines is applicable to the food preferences of different racial/ethnic groups, vegetarians, and other groups. This concept of balanced eating patterns should be utilized in planning diets for various population groups.
There is a growing body of evidence which demonstrates that following a diet that complies with the Dietary Guidelines may reduce the risk of chronic disease. Recently, it was reported that dietary patterns consistent with recommended dietary guidance were associated with a lower risk of mortality among individuals age 45 years and older in the United States. 4 The authors of the study estimated that about 16 percent and 9 percent of mortality from any cause in men and women, respectively, could be eliminated by the adoption of desirable dietary behaviors. Currently, adherence to the Dietary Guidelines is low among the U.S. population. Data from USDA illustrate the degree of change in the overall dietary pattern of Americans needed to be consistent with a food pattern encouraged by the Dietary Guidelines (fig. 1).
A basic premise of the Dietary Guidelines is that nutrient needs should be met primarily through consuming foods. Foods provide an array of nutrients (as well as phytochemicals, antioxidants, etc.) and other compounds that may have beneficial effects on health. In some cases, fortified foods may be useful sources of one or more nutrients that otherwise might be consumed in less than recommended amounts. Supplements may be useful when they fill a specific identified nutrient gap that cannot or is not otherwise being met by the individual’s intake of food. Nutrient supplements cannot replace a healthful diet. Individuals who are already consuming the recommended amount of a nutrient in food will not achieve any additional health benefit if they also take the nutrient as a supplement. In fact, in some cases, supplements and fortified foods may cause intakes to exceed the safe levels of nutrients. Another important premise of the Dietary Guidelines is that foods should be prepared and handled in such a way that reduces risk of foodborne illness.
USES OF THE DIETARY GUIDELINES
The Dietary Guidelines is intended primarily for use by policymakers, healthcare providers, nutritionists, and nutrition educators. While the Dietary Guidelines was developed for healthy Americans 2 years of age and older, where appropriate, the needs of specific population groups have been addressed. In addition, other individuals may find this report helpful in making healthful choices. As noted previously, the recommendations contained within the Dietary Guidelines will aid the public in reducing their risk for obesity and chronic disease. Specific uses of the Dietary Guidelines include:
Development of Educational Materials and Communications.
The information in the Dietary Guidelines is useful for the development of educational materials. For example, the federal dietary guidancerelated publications are required by law to be based on the Dietary Guidelines . In addition, this publication will guide the development of messages to communicate the Dietary Guidelines to the public. Finally, the USDA Food Guide, the food label, and Nutrition Facts Panel provide information that is useful for implementing the key recommendations in the Dietary Guidelines and should be integrated into educational and communication messages.
Development of NutritionRelated Programs.
The Dietary Guidelines aids policymakers in designing and implementing nutritionrelated programs. The Federal Government bases its nutrition programs, such as the National Child Nutrition Programs or the Elderly Nutrition Program, on the Dietary Guidelines .
Development of Authoritative Statements.
The Dietary Guidelines has the potential to provide authoritative statements as provided for in the Food and Drug Administration Modernization Act (FDAMA). Because the recommendations are interrelated and mutually dependent, the statements in this publication should be used together in the context of an overall healthful diet. Likewise, because the Dietary Guidelines contains discussions about emerging science, only statements included in the Executive Summary and the highlighted boxes entitled “Key Recommendations,” which reflect the preponderance of scientific evidence, can be used for identification of authoritative statements.
4 Kant AK, Graubard BI, Schatzkin A. Dietary patterns predict mortality in a national cohort: The national health interview surveys, 1987 and 1992. Journal of Nutrition (J Nutr) 134:17931799, 2004.
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FIGURE 1. Percent Increase or Decrease From Current Consumption (Zero Line) to Recommended Intakes a,b Agraphical depiction of the degree of change in average daily food consumption by Americans that would be needed to be consistn with the foodpatterns encouraged by the Dietary Guidelines for Americans .The zero line represents average consumption levels from each food group or subgroup byfemales 31 to 50 years of age and males to 50 years of age. Bars above the zero line represent recommended increases in food group consumption,while bars below the line represent recommended decreases.A c
aUSDA Food Guide in comparison to National Health and Nutrition Examination Survey 20012002 consumption data.bIncreases in amounts of some food groups are offset by decreases in amounts of solid fats (i.e., saturated and trans fats) and added sugars so that total calorie intake is at the recommended level.
5 c
Adequate Nutrients Within Calorie Needs
OVERVIEW Many Americans consume more calories than they need without meeting recommended intakes for a number of nutrients. This circumstance means that most people need to choose meals and snacks that are high in nutrients but low to moderate in energy content; that is, meeting nutrient recommendations must go hand in hand with keeping calories under control. Doing so offers important benefits—normal growth and development of children, health promotion for people of all ages, and reduction of risk for a number of chronic diseases that are major public health problems.
Based on dietary intake data or evidence of public health problems, intake levels of the following nutrients may be of concern for: • Adults: calcium, potassium, fiber, magnesium, and vitamins A (as carotenoids), C, and E, • Children and adolescents: calcium, potassium, fiber, magnesium, and vitamin E, • Specific population groups (see below): vitamin B 12 , iron, folic acid, and vitamins E and D. At the same time, in general, Americans consume too many calories and too much saturated and trans fats, cholesterol, added sugars, and salt.
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DISCUSSION Meeting Recommended Intakes Within Energy Needs A basic premise of the Dietary Guidelines is that food guidance should recommend diets that will provide all the nutrients needed for growth and health. To this end, food guidance should encourage individuals to achieve the most recent nutrient intake recommendations of the Institute of Medicine , referred to collectively as the Dietary Reference Intakes (DRIs). Tables of the DRIs are provided at http://www.iom.edu/Object.File/Master/21/372/0.pdf. An additional premise of the Dietary Guidelines is that the nutrients consumed should come primarily from foods. Foods contain not only the vitamins and minerals that are often found in supplements, but also hundreds of naturally occurring substances, including carotenoids, flavonoids and isoflavones, and protease inhibitors that may protect against chronic health conditions. There are instances when fortified foods may be advantageous, as identified in this chapter. These include providing additional sources of certain nutrients that might otherwise be present only in low amounts in some food sources, providing nutrients in highly bioavailable forms, and where the fortification addresses a documented public health need. Two examples of eating patterns that exemplify the Dietary Guidelines are the DASH Eating Plan and the USDA Food Guide. These two similar eating patterns are designed to integrate dietary recommendations into a healthy way to eat and are used in the Dietary Guidelines to provide examples of how nutrientfocused recommendations can be expressed in terms of food choices. Both the USDA Food Guide and the DASH Eating Plan differ in important ways from common food consumption patterns in the United States . In general, they include: • More dark green vegetables, orange vegetables, legumes, fruits, whole grains, and lowfat milk and milk products. • Less refined grains, total fats (especially cholesterol, and saturated and trans fats), added sugars, and calories.
KEY RECOMMENDATIONS • Consume a variety of nutrientdense foods and beverages within and among the basic food groups while choosing foods that limit the intake of saturated and trans fats, cholesterol, added sugars, salt, and alcohol. • Meet recommended intakes within energy needs by adopting a balanced eating pattern, such as the USDA Food Guide or the DASH Eating Plan. Key Recommendations for Specific Population Groups • People over age 50. Consume vitamin B 12 in its crystalline form (i.e., fortified foods or supplements). • Women of childbearing age who may become pregnant. Eat foods high in hemeiron and/or consume ironrich plant foods or ironfortified foods with an enhancer of iron absorption, such as vitamin Crich foods. • Women of childbearing age who may become pregnant and those in the first trimester of pregnancy. Consume adequate synthetic folic acid daily (from fortified foods or supplements) in addition to food forms of folate from a varied diet. • Older adults, people with dark skin, and people exposed to insufficient ultraviolet band radiation (i.e., sunlight). Consume extra vitamin D from vitamin Dfortified foods and/or supplements. Both the USDA Food Guide and the DASH Eating Plan are constructed across a range of calorie levels to meet the nutrient needs of various age and gender groups. Table 1 provides food intake recommendations, and table 2 provides nutrient profiles for both the DASH Eating Plan and the USDA Food Guide at the 2,000calorie level. These tables illustrate the many similarities between the two eating patterns. Additional calorie levels are shown in appendixes A1 and A2 for the USDA Food Guide and the DASH Eating Plan. The exact amounts of foods in these plans do not need to be achieved every day, but on average, over time. Table 3 can aid in identification of an individual’s caloric requirement based on gender, age, and physical activity level.
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Variety Among and Within Food Groups
Each basic food group 5 is the major contributor of at least one nutrient while making substantial contributions of many other nutrients. Because each food group provides a wide array of nutrients in substantial amounts, it is important to include all food groups in the daily diet.
Both illustrative eating patterns include a variety of nutrientdense foods within the major food groups. Selecting a variety of foods within the grain, vegetable, fruit, and meat groups may help to ensure that an adequate amount of nutrients and other potentially beneficial substances are consumed. For example, fish contains varying amounts of fatty acids that may be beneficial in reducing cardiovascular disease risk (see ch. 6).
NutrientDense Foods
Nutrientdense foods are those foods that provide substantial amounts of vitamins and minerals (micronutrients) and relatively few calories. Foods that are low in nutrient density are foods that supply calories but relatively small amounts of micronutrients, sometimes none at all. The greater the consumption of foods or beverages that are low in nutrient density, the more difficult it is to consume enough nutrients without gaining weight, especially for sedentary individuals. The consumption of added sugars, saturated and trans fats, and alcohol provides calories while providing little, if any, of the essential nutrients. (See ch. 7 for additional information on added sugars, ch. 6 for information on fats, and ch. 9 for information on alcohol.)
Selecting lowfat forms of foods in each group and forms free of added sugars—in other words nutrientdense versions of foods—provides individuals a way to meet their nutrient needs while avoiding the overconsumption of calories and of food components such as saturated fats. However, Americans generally do not eat nutrientdense forms of foods. Most people will exceed calorie recommendations if they consistently choose higher fat foods within the food groups—even if they do not have dessert, sweetened beverages, or alcoholic beverages.
If only nutrientdense foods are selected from each food group in the amounts proposed, a small amount of calories
can be consumed as added fats or sugars, alcohol, or other foods—the discretionary calorie allowance. Appendixes A2 and A3 show the maximum discretionary calorie allowance that can be accommodated at each calorie level in the USDA Food Guide. Eating in accordance with the USDA Food Guide or the DASH Eating Plan will also keep intakes of saturated fat, total fat, and cholesterol within the limits recommended in chapter 6.
Nutrients of Concern
The actual prevalence of inadequacy for a nutrient can be determined only if an Estimated Average Requirement (EAR) has been established and the distribution of usual dietary intake can be obtained. If such data are not available for a nutrient but there is evidence for a public health problem associated with low intakes, a nutrient might still be considered to be of concern.
Based on these considerations, dietary intakes of the following nutrients may be low enough to be of concern for:
- Adults: calcium, potassium, fiber, magnesium, and vitamins A (as carotenoids), C, and E,
- Children and adolescents: calcium, potassium, fiber, magnesium, and vitamin E,
Specific population groups: vitamin B 12 , iron, folic acid, and vitamins E and D. |
