Dietary fibre helps check weight: Study

New York: By studying the diets of 52 normal-weight adults and 52 overweight or obese adults, researchers found that normal-weight adults ate more fibre and fruit each day than their overweight and obese counterparts.

"These findings suggest that the composition of a diet, especially low dietary fibre and fruit intake, play a role in the development of obesity," concludes the study team in the Journal of the American Dietetic Association.

For all study subjects, Dr Jaimie N. Davis of the University of Southern California in Los Angeles and colleagues determined the dietary amount of 60 food items using a food frequency questionnaire.

They assessed physical activity levels and determined per cent body fat.

All of the subjects were about the same age and height.

Davis' group found marked differences in the dietary habits of the two groups.

The overweight and obese subjects consumed more total fat, saturated fat and cholesterol, and less carbohydrate, specifically dietary fibre and complex carbohydrate than normal weight subjects.

The differences in diet composition "may have played a vital role in promoting or preventing obesity," they write.

Normal-weight adults consumed an average of 33 per cent more dietary fibre and 43 per cent more complex carbohydrates daily than their overweight and obese counterparts.

Dietary fibre and complex carbohydrate intake were inversely related to body weight and "most strongly" to percent body fat.

Compared with normal-weight subjects, overweight and obese subjects consumed about one less fruit serving daily, which may partly explain their lower fibre and carbohydrate intake.

There are several mechanisms by which dietary fibre may reduce the risk of weight gain or obesity.

Dietary fibre , for example, slows digestion, prolonging that "full" feeling and foods high in fibre are usually low in fat and calories.

"The public is still attracted to popular weight-loss strategies that emphasize decreasing carbohydrate and increasing fat and protein," the study team notes in their report.

"Although there is evidence that high-protein, low-carbohydrate diets produce substantial weight loss in the short-term, to date there are no long-term studies that examine the effects of these regimens,” they add.

While there is no magic formula for weight loss, in the current study, "dietary fibre, complex carbohydrates and fruit were associated with lower body fat stores in adults," Davis said.

"These results suggest that increasing dietary fiber, complex carbohydrates and fruit in an individual's diet should be an important part of dietary interventions," the researcher concluded.