Researchers at the University of Arkansas for Medical Sciences (UAMS) show in the journal Archives of Internal Medicine today that older people can lose weight on a diet rich in complex carbohydrates, even if they eat until they are satisfied and do not reduce the calories they consume.

"Our study suggests that eating a diet low in fat and rich in carbohydrates is better than counting calories for people who need to lose weight," said William J. Evans, professor in the Donald W. Reynolds Department of Geriatrics in the UAMS College of Medicine.

In a 12-week experiment funded by the National Institute on Aging, the UAMS researchers found that a low-fat, high-carbohydrate diet, with or without aerobic exercise, clearly supported weight loss in overweight men and women ages 56 to 78 years of age. Volunteers eating all they wanted of foods, with no more than 20 percent dietary fat, lost significant weight and body fat. Volunteers who also exercised regularly lost even more weight. The average weight loss in the study was almost 11 pounds.

The findings are in contrast to claims that high-carbohydrate foods create more body fat than do low-carbohydrate foods, and that it's easier to restrict calories on a high-fat diet because the dieter feels more satisfied.

"Our findings refute the claims that low-fat, high-carbohydrate diets cause more body fat and leave dieters less satisfied," Evans said. "To the contrary, a diet with no more than 20 percent fat appears to be easy and effective for overweight individuals, particularly those with a high risk of developing type 2 diabetes."

Comparing results of volunteers in three groups, the UAMS researchers also found that volunteers on the low-fat diet did not experience a reduction in metabolic rate, as dieters on low-calorie plans often do.

In Evans' study, volunteers who were a risk of developing type 2 diabetes ate as much as they liked of selected, low-fat, high-carbohydrate foods, for an overall diet that was no more than 20 percent dietary fat. The volunteers returned any uneaten food for the researchers to weigh, so the total calories and fat content of the foods each volunteer consumed could be accurately determined.

A randomly selected subgroup also exercised four times per week on a stationary cycle. A third group ate a different diet with 40 percent from fat and did not exercise. All of the volunteers in the study were overweight and sedentary.

Evans is director of the Nutrition, Metabolism, and Exercise Laboratory in the Donald W. Reynolds Department of Geriatrics, College of Medicine, UAMS, and is affiliated with the Central Arkansas Veterans Healthcare System.