ABSTRACT: The new dietary guidelines provide specific advice for health and nutrition policy professionals about what constitutes a healthy diet for selected population groups.

The 2005 Dietary Guidelines for Americans, issued every 5 years by the United States Department of Agriculture (USDA), set high nutritional objectives for the public, UAB nutrition scientist Douglas C. Heimburger, MD, says.

The expert panel who authored the 70-page report based its extensive, and, for the first time, highly specific recommendations, on review of the most current scientific literature (Available at: www.healthierus.gov/dietaryguidelines. Accessed August 30, 2005).

“Public health recommendations tend to fall into one of two categories: easily digestible, but not overly specific or ambitious suggestions, or more complex guidelines that embody the best scientific evidence, but may be hard for the public to understand and even harder for them to implement. The latest guidelines clearly fall into the latter category,” he says.

The 2005 guidelines recommend individuals adhere either to the USDA Food Guide or the Dietary Approaches to Stop Hypertension Eating Plan (Available at:www.nhlbi.nih.gov/health/public/heart/hbp/dash. Access August 30, 2005). The new report notes these eating patterns are not weight loss diets, but rather, illustrative examples of how to eat in accordance with the Dietary Guidelines.

The 2005 guidelines have 41 key recommendations that include 9 servings of fruit and vegetables a day, a daily sodium limit of 2300 mg (approximately 1 teaspoon of salt), and 60 minutes of moderate-to-vigorous exercise on most days to prevent weight gain.

In comparison, the 2000 guidelines offered 10 comparatively vague recommendations, such as “aim for a healthy weight” and “choose a variety of fruits and vegetables each day,” and did not provide details such as serving sizes and specific physical activity levels needed to lose or maintain weight. Other additions to the 2005 guidelines are the recommendations for specific population groups, including children and adolescents, older adults, and pregnant women (see box).

“In nutrition science, as in the rest of medicine, one size definitely does not fit all,” Heimburger says. “Blacks, for example, have higher rates of hypertension than whites, and the 2005 guidelines reflect that disparity by recommending blacks and other individuals in high-risk groups limit sodium intake to 1500 mg a day. Distinctions among different populations will continue growing in importance as more research emerges on links among disease, nutrition, and genetics.”

My Pyramid

Unlike earlier versions of the Dietary Guidelines, the 2005 version targets policy makers, nutrition educators, and health providers, not the general public. For the public, USDA has distilled much of the information into an interactive Web site — www.mypyramid.gov — featuring the revamped food pyramid and “My Pyramid” program that lets consumers create personalized eating plans based on age, gender, and activity level.

Instantly generated individualized plans offer daily calorie limits, including a “discretionary calorie” (extra fats and sugars) allowance, specific food group recommendations, such as eating 2.5 cups of vegetables, 2 cups of fruit, 3 cups of milk, 6 oz of grains, and 5.5 oz of meat/beans a day, and tips for incorporating these foods into a daily diet. Other features include a meal-tracking worksheet and daily nutrition and exercise tips. The site also includes a link to USDA’s Interactive Healthy Eating Index, an online dietary assessment tool that analyzes nutrient content of individual diets and offers links to nutrient information.

Heimburger notes the 2005 guidelines have been criticized for applicability in real-life settings. “For instance, the average person will have to plan carefully to meet all the recommended intakes, such as 3 oz or more of whole grain products, 3 cups of fat-free or low-fat dairy products, and 9 servings of fruit and vegetables, while still staying within their recommended calorie limits,” he says.

“But, these guidelines are closer to the ‘gold standard’ of nutrition and physical activity advice than previous versions, precisely because they are so explicit and do not stop short of recommending what scientific evidence suggests,” he continues. “There are pros and cons to this level of detail. These are generally excellent recommendations, but some people may be discouraged because of the guidelines’ complexity and the difficulty of incorporating such changes into busy lifestyles.”

Other Changes
Sugars

The 2005 guidelines caution individuals to limit added sugars; earlier guidelines simply advised moderating sugar intake. “By including the term ‘added,’ the guidelines are attempting to steer people away from highly processed foods and sugar-sweetened soft drinks and toward nutrient-dense food sources,” Heimburger says.

Fata

The 2005 guidelines make a distinction between different types of fats, stating individuals should limit total fat to 20% to 30% of daily calories, with most fats coming from polyunsaturated or monounsaturated fat sources.

“This is one of the best changes,” he says. “Newer evidence shows that not all fats are created equal. People who eat diets such as the Mediterranean diet, which is high in monounsaturated fat, have lower rates of heart disease and cancer, while eating excess amounts of foods high in trans-fats favors development of atherosclerosis.”

As of January 1, 2006, the Food and Drug Administration will require food labels to include the amount of trans-fatty acids in food products. The 2005 guidelines include a number of useful tables to help people identify significant sources of fat and sugar in their diet.

Diet and Disease Prevention

“There is an increasing focus on preventing and managing disease through diet, and the 2005 guidelines reflect this philosophy,” Heimburger says.

The guidelines note that, compared with individuals who eat few fruits and vegetables, those who eat more generous amounts are at reduced risk of chronic diseases, such as stroke and other cardiovascular diseases, type 2 diabetes, and certain cancers (oral cavity and pharynx, larynx, lung, esophagus, stomach, and colorectal).

A recent systematic review of literature on dietary patterns, lifestyle, demographic variables, and health outcomes found a protective effect with healthful dietary patterns; the most consistently positive association was between healthy diet and all-cause mortality and cardiovascular disease risk. Yet, the study authors note the magnitude of risk reduction in most studies was modest, and other desirable health behaviors created a confounding effect (J Am Diet Assoc. 2004;104:615-635).

The 2005 Dietary Guidelines also link increased dairy consumption to improved health, noting higher dairy consumption reduces risk of low bone mass and contributes important nutrients such as calcium, potassium, magnesium, vitamin D, and vitamin A.

Some studies also suggest high fat-free or low-fat dairy consumption contributes to weight loss, but Heimburger advises caution when interpreting results (Int J Obes Relat Metab Disord. 2005;[4]:391-397 and Obes Res. 2004;[4]:582-590).

“In the last 5 years, more evidence of dairy’s beneficial effects has emerged,” he says. “Yet, many studies linking dairy consumption and weight loss have been conducted in a single lab; more research is needed to understand the interaction between dairy consumption and weight loss. But, most children do not get even one daily serving of dairy products, and fat-free and low-fat dairy foods play an important role in a healthy diet.”

The Dietary Guidelines for Americans are the foundation of federal nutrition policy, setting nutrition standards for federal programs such as the National School Lunch Program, School Breakfast Program, Food Stamps, and the Special Supplemental Program for Women, Infants, and Children (Nutrition Today. 2003;38[6]:204-217).

“The panel hopes the 2005 guidelines will have a trickle-down effect to cafeterias in schools, institutions, and workplaces,” Heimburger says. “For guidance and advice for individual patients, physicians can use educational material available through the ‘My Pyramid’ Web site and should also consider advocating reimbursement for dietitians, whose time can be dedicated to helping patients understand and apply these valuable, but complex, guidelines.”