Following the nation's dietary recommendations not only provides good nutrition but can also result in sustained loss of excess weight and improvements in other factors known to contribute to heart disease, according to researchers at the University of California, Davis, and the Oregon Health Sciences University in Portland. During a yearlong study, Judith Stern, a UC Davis professor of nutrition and internal medicine, and David McCarron, formerly the head of the Division of Nephrology at OHSU, and colleagues assessed the effect on weight loss of a comprehensive diet incorporating the dietary guidelines of national health organizations. Their findings are reported in the July 24 issue of the journal Archives of Internal Medicine. "The study demonstrates that meeting the current dietary recommendations for eating appropriate amounts of a variety of healthy foods is an effective way to lose excess weight and maintain optimal weight," Stern said. She speculates that this will prove to be the most healthful approach to weight loss and management, compared to diet programs focused on changing the intake of a single component of the diet, such as fat or sugar. "Furthermore, the results of this study indicate that individuals who follow the dietary guidelines also can reduce their risk of cardiovascular disease, as measured in terms of the simultaneous improvements we observed in cholesterol and triglyceride levels, blood pressure, blood sugar balance and participants' quality of life," added Jill Metz, an assistant professor of medicine at OHSU and the lead author on the study. This latest report from a seven-year series of intervention trials assessing effects of diet on cardiovascular disease risk factors is unique among diet studies in its lengthy one-year duration, large number of participants, and randomized, controlled study design. The current study involved more than 300 overweight or obese participants, including 183 with hypertension and elevated cholesterol levels, and 119 with adult-onset diabetes. The controlled research trials were conducted at five university medical centers including the University of Alabama at Birmingham, Pennsylvania State University and Columbia University, in addition to UC Davis and OHSU. Patients in both the hypertension and diabetes groups followed one of two meal plans. Participants consumed either a comprehensive, prepackaged meal plan provided to them that met all recommendations for vitamins, minerals, fiber, fats and sodium, or they prepared their own meals using dietary instructions that are typically recommended for people at greater risk for heart disease. The latter approach is designed to lower calorie and fat intake and increase fiber and mineral consumption. Greater weight loss Participants in both the hypertensive and diabetic groups who ate the balanced prepared meals lost significantly more weight than did those on the typical risk-reduction diet. Those in the hypertensive group on the prepared-meal plan lost an average of 17.2 pounds by the 26th week and 12.8 pounds by the end of the year. Their final average weight loss was 74 percent of the mid-study loss, reflecting a slight gain that commonly follows initial weight loss among dieters. Using the typical risk-reduction diet approach, hypertensive participants lost an average of 5.3 pounds by the 26th week and 3.8 pounds by the end of the year. Their final average weight loss was 71 percent of the mid-study loss. Among the diabetic group, those on the prepared-meal plan averaged 12 pounds of weight loss by week 26 and 55 percent of that loss was maintained by the end of the one-year study. Diabetic participants on the typical risk-reduction diet averaged weight loss of 3.3 pounds by the middle of the study and 1 pound at the end of the study. More dieters losing weight Fifty-seven percent of the hypertensive group consuming the comprehensive meal plan achieved a weight loss of at least 5 percent of initial weight. In contrast, this was accomplished by only 19 percent of hypertensive persons assigned to the typical risk-reduction diet. In the diabetes group, 29 percent of participants achieved at least a 5 percent loss from their initial weight on the comprehensive diet plan compared with 10 percent of those assigned to the typical risk-reduction diet. At the year's end, the researchers also checked to see how closely the participants complied with the American Heart Association Step 1 dietary recommendations, which are commonly given to people at increased risk for heart disease. Overall, compliance among those on the comprehensive meal plan was twice that of those on the typical risk-reduction diet. Among hypertensive participants, compliance on the former was 75 percent and on the latter was 37 percent. In the diabetes group, compliance on the former was 68 percent and on the latter was 33 percent. Conclusions "In short, the study clearly establishes that significant weight loss can be achieved and sustained by simply following the recommended dietary guidelines to assure appropriate intake levels of all nutrients and vitamins," Stern said. "It also confirms that weight-loss programs that simply follow national dietary recommendations for a balanced diet are more successful than unbalanced weight-loss programs in producing multiple, sustainable cardiovascular benefits, and in doing so without medication, excessive cost or adverse side effects," McCarron said. The study was supported by a grant from the Campbell Soup Company.