Diet, the combination of foods consumed and the manner in which the foods are consumed, provides both energy and nutrients to support growth and maintain tissue health. Foods also contain nonnutrients that provide health benefits (such as phytochemicals and fiber) or are associated with chronic disease (such as cholesterol and saturated fatty acids). The distribution of energy, nutrients and nonnutrients varies among foods both within and among food groups. Dietary guidance is designed to assist the consumer in selecting foods to promote both oral and systemic health and prevent chronic disease.
The U.S. Department of Agriculture (USDA) is responsible for critiquing the best available science from human observational studies, clinical trials and animal studies to develop the scientific foundation for dietary guidance. The USDA defines optimal nutrient intakes, the types and amounts of foods necessary to achieve optimal nutrient intakes and the nutrients and nonnutrients to avoid in attempting to prevent chronic disease. The USDA offers three levels of dietary guidance: the Dietary Reference Intakes,1 which outline individual nutrient intake recommendations; MyPyramid,2 which outlines dietary patterns of grains, vegetables, fruits, milk, meat and beans, and oils; and the Dietary Guidelines for Americans,3 which are designed to promote healthy lifestyles and dietary habits.
The USDA institutes a review of the Dietary Guidelines for Americans every five years to consider new science, changes in the food supply and environmental influences. The USDA’s recently released Dietary Guidelines for Americans, 2010, published in conjunction with the U.S. Department of Health and Human Services, acknowledges the nation’s obesity epidemic, which is associated with both poor food choices and decreased physical activity. Two themes permeate the 2010 guidelines3:
– the need to maintain calorie balance to support a healthy weight;
– the need to select nutrient-dense foods and beverages to ensure adequate nutrient intake within energy requirements.
The U.S. population is experiencing unprecedented rates of obesity and obesity-related chronic disease in spite of the scientific soundness of earlier guidelines and dietary patterns (such as MyPyramid2). Unfortunately, compliance with the guidelines and dietary patterns historically has been limited, and the chasm between the recommendations and people’s actual dietary practices continues to widen.4,5,6 The 2010 guidelines highlight the difficulties consumers face when making food choices.3 A socioecological model describes factors influencing food choices in the context of individual factors, environmental settings and social and cultural norms and acknowledges the role of sectors of influence such as the government; public health systems; agriculture; marketing; and the food, beverage and entertainment industries. The 2010 guidelines emphasize that to make more healthful food choices, all Americans must have access to healthy foods. Furthermore, individual change will necessitate environmental change, and optimal dietary habits begin early and last throughout life.
DIETARY GUIDELINES FOR AMERICANS, 2010
The guidelines are organized into four themes: balancing calorie intake to manage weight, reducing consumption of certain foods and food components, increasing consumption of certain foods and nutrients and building healthy eating patterns.3 Each theme is accompanied by specific recommendations.
Balancing calories to manage weight
– Prevent and/or reduce overweight and obesity through improved eating and physical activity behaviors.
– Control total calorie intake to manage body weight. For people who are overweight or obese, this will mean consuming fewer calories from foods and beverages.
– Increase physical activity and reduce time spent in sedentary behaviors.
– Maintain appropriate calorie balance during each stage of life—childhood, adolescence, adulthood, pregnancy and breastfeeding, and older age.
Foods and food components to reduce
– Reduce daily sodium intake to less than 2,300 milligrams and further reduce intake to 1,500 mg among people who are aged 51 years and older and those of any age who are African American or who have hypertension, diabetes or chronic kidney disease. The 1,500 mg recommendation applies to about one-half of the U.S. population, including children, and the majority of adults.
– Consume less than 10 percent of calories from saturated fatty acids by replacing them with monounsaturated and polyunsaturated fatty acids.
– Consume less than 300 mg per day of dietary cholesterol.
– Keep trans fatty acid consumption as low as possible by limiting foods that contain synthetic sources of trans fats, such as partially hydrogenated oils, and by limiting other solid fats.
– Reduce the intake of calories from solid fats and added sugars.
– Limit the consumption of foods that contain refined grains, especially refined grain foods that contain solid fats, added sugars and sodium.
– If alcohol is consumed, it should be consumed in moderation—up to one drink per day for women and two drinks per day for men—and only by adults of legal drinking age.
Foods and nutrients to increase
People should meet the following recommendations as part of a healthy eating pattern while staying within their caloric needs.
– Increase vegetable and fruit intake.
– Eat a variety of vegetables, especially dark green and red and orange vegetables and beans and peas.
– Consume at least one-half of all grains as whole grains. Increase whole-grain intake by replacing refined grains with whole grains.
– Increase intake of fat-free or low-fat milk and milk products, such as milk, yogurt, cheese or fortified soy beverages.
– Choose a variety of protein foods, which include seafood, lean meat and poultry, eggs, beans and peas, soy products, and unsalted nuts and seeds.
– Increase the amount and variety of seafood consumed by choosing seafood in place of some meat and poultry.
– Replace protein foods that are higher in solid fats with choices that are lower in solid fats and calories and/or are sources of oils.
– Use oils to replace solid fats where possible.
– Choose foods that provide more potassium, dietary fiber, calcium and vitamin D, which are nutrients of concern in American diets. These foods include vegetables, fruits, whole grains, and milk and milk products.
Building healthy eating patterns
– Select an eating pattern that meets nutrient needs across time at an appropriate calorie level.
– Account for all foods and beverages consumed and assess how they fit within a total healthy eating pattern.
– Follow food safety recommendations when preparing and eating foods to reduce the risk of foodborne illnesses.
1.U.S. Department of Agriculture, National Agricultural Library, Food and Nutrition Information Center. Dietary Guidance: Dietary Reference Intakes. "http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=2&tax_subject=256&level3_id=0&level4_id=0&level5_id=0&topic_id=1342&&placement_default=0". Accessed April 26, 2011.
3.U.S. Department of Agriculture, Center for Nutrition Policy and Promotion. Dietary Guidelines for Americans, 2010. "www.cnpp.usda.gov/dietaryguidelines.htm". Accessed April 5, 2011.
4.Centers for Disease Control and Prevention. State-specific trends in fruit and vegetable consumption among adults: United States, 2000–2009. MMWR Morb Mortal Wkly Rep 2010;59(35): 1125–1130.
5. Daniel CR,
. Trends in meat consumption in the USA. Public Health Nutr 2010;14(4):575–583.