Issue 145 Item 12 Dietary Counseling a Must for High-Risk Patients

That, according to new recommendations from the U.S. Preventive Services Task Force. What troubles many physicians about dietary counseling is how to do it. But do it they must—for high-risk patients. The task force found sufficient evidence that dietary counseling improves the health of patients who have high cholesterol, diabetes, a weight problem, or other chronic disease risk factors. But the task force did not find enough evidence to recommend routine dietary counseling for the general adult population.

The task force, an independent panel of primary care physicians and preventive medicine experts, published the recommendations online at the Web site of the Agency for Healthcare Research and Quality and in the January 2003 issue of the American Journal of Preventive Medicine (Am. J. Prev. Med. 24[1]:84-101, 2003).

For high-risk patients, the task force recommendation in favor of dietary counseling carried a grade of “B” (on a scale where “A” means “strongly recommends” and “D” means “recommends against”). For the general population, dietary counseling received a grade of “I” (insufficient evidence).

At the task force’s request, Dr. Michael P. Pignone of the University of North Carolina at Chapel Hill and his colleagues analyzed 21 randomized, controlled trials of dietary intervention published between 1966 and 2001. The studies were rated high, medium, or low intensity, and included patients with and without chronic disease risk factors. The effects of the interventions were defined as large, medium, or small to none.

Factors influencing the effectiveness of dietary counseling included the intervention intensity and setting, patient’s risk factors, and the use of counseling techniques shown to induce behavioral change. For example, large changes in dietary behavior were noted in five of nine high-intensity studies. Of the 17 studies that evaluated the effect of counseling on saturated fat intake, 6 resulted in a reduction greater than 3%, 5 resulted in reductions from 1.3% to 3%, and 6 resulted in reductions of less than 1.3%.

Of the 10 studies that evaluated the effect of counseling on fruit and vegetable intake, 2 showed large effects (consumption increased by 1.4 and 3.2 servings per day, respectively). Five studies showed medium increases (from 0.3 to 0.8 servings per day), and three studies showed that dietary counseling yielded no increase or small increases (of less than 0.3 servings per day).

Of the seven studies that evaluated the effect of counseling on fiber intake, five showed increases ranging from 0.3 g to 1.6 g per day; one study showed a net increase of 3 g for the intervention group vs. the control group. A seventh study showed a 2.7-g increase for men in the intervention vs. the control group, and a 6-g increase for women in the intervention group.

Dietary interventions at research clinics generally were more effective in changing behavior than interventions at primary care clinics; few studies have evaluated patients referred by primary care physicians to other health care professionals, the researchers noted.

Many adults with chronic disease risk factors fall short of basic nutritional guidelines. For example, findings from the Third National Health and Nutrition Examination Survey (NHANES III) indicated that 60% of 1,480 adults with type 2 diabetes reported that they follow a “diabetic diet,” and 62% reported eating fewer than five servings of fruits and vegetables daily . Diabetes Care 25 [10]:1722-28, 2002).