printable version5 Questions: Gardner on new dietary guidelines
An occasional feature in which a medical expert answers five questions on a science or policy topic of interest to the Stanford community
Christopher Gardner
The U.S. Departments of Agriculture and of Health and Human Services unveiled new dietary guidelines last week in a bid to improve Americans’ eating and exercise habit. But can the guidelines help stem the rising tide of obesity in this country? For a look at their potential impact, Susan Ipaktchian, communication director in the Office of Communication & Public Affairs, spoke with nutrition expert Christopher Gardner, PhD, assistant professor (research) of medicine at the Stanford Prevention Research Center.
1. If, as HHS Secretary Tommy Thompson says, the new guidelines are “common sense,” why is it so hard for people to follow them?
Gardner: Common sense provides little protection in a toxic environment. If the school, workplace or neighborhood environment limits access to healthy foods and physical activity, then despite a person’s understanding of good health, their success in following these guidelines will be limited.
2. Are the guidelines a big departure from previous versions?
Gardner: There have been new versions every five years since 1980. The first four versions involved seven basic messages with simple refinements in wording and ranking. The 2000 version contained 10 guidelines. The latest version—which contains nine general topics and 41 key recommendations—represents the most dramatic change yet.
The key recommendations include more specific language and topics that were not addressed previously. Most notable is the recommendation to get not just 30, but 60 or even 90 minutes of daily physical activity, depending on whether you want to maintain your weight or lose weight. Also notable and laudable are the specific recommendations to get at least half of your daily grain intake from whole-grain products, eat 2 1/2 cups of vegetables and 2 cups of fruit each day and limit trans-fats. In particular, the shift in wording for vegetables and fruits from specific “servings” in 2000 to “cups” in 2005 is a welcome change, making the language of the recommendations easier for the average person to understand.
3. School lunch programs have used the guidelines for years, and yet more American children are overweight than ever before. Can the new guidelines change that?
Gardner: Not until these recommendations are followed and enforced at schools. A substantial portion of the foods provided to school food-service programs currently do not even meet the USDA’s own guidelines. Fewer schools have adequate facilities for producing food, so more fast-food establishments and vending machines have made their way into the schools. Even when the schools do provide some healthy choices, these often compete with the fast-food outlets and vending machines. Physical education requirements in schools have been undercut or eliminated for the sake of more time to meet state academic requirements.
4. When it comes to diet and exercise, how much responsibility rests with physicians?
Gardner: Unfortunately, even the best advice of physicians and the best intentions of patients to modify their diet and exercise behaviors are undermined by environmental conditions. Those conditions include absurdly large portion sizes in restaurants, well-financed design and promotion of unhealthy fast foods, political conflicts of interest (i.e. the USDA being responsible for generating national dietary guidelines while at the same time representing the National Cattleman’s Association and the Dairy Council as its constituents), and limited availability of places to walk or be physically active. Nonetheless, physicians are in a good position to increase the awareness of their patients while these major obstacles are being addressed. Physicians increasingly recognize that the responsibility to provide advice on diet and physical activity falls within the boundaries of clinical practice.
5. Do physicians know how to provide meaningful diet and exercise advice to their patients?
Gardner: General advice, yes. Beyond that, the answer is often no. Historically, medical schools have made nominal efforts to educate students about nutrition and physical activity, though that is improving somewhat, including at Stanford. Given the potential impact of physicians in these important areas, more training should be provided, and physicians should work more closely with both dietitians and exercise counselors. Current insurance reimbursement policies inhibit such collaboration—rarely covering nutritional advice, for example—and severely limit the time available to physicians to counsel patients themselves.