Visceral Fat Loss After Dieting is Not Necessarily Responsible For Disease Risk Improvements

November 2002 - Weight-loss related changes in risk factors for diabetes and cardiovascular disease (CVD) are often linked to visceral fat, rather than other types of fat deposits, especially in people with different racial and ethnic backgrounds.

In a new study in the American Journal of Clinical Nutrition, Gower et al. compared the locations in which white and African American women lost body fat in order to determine the potential influence of the location of fat loss on disease risk factors. Both racial groups experienced significant improvements in blood lipids and insulin sensitivity, and the beneficial effects of weight loss could not be attributed to any particular location of fat loss.

Participants in the study were all initially overweight and consisted of 18 white and 19 African American women who ranged in age from 21 to 46 years. They consumed a clinically controlled diet that provided 800 kcal per day until each subject had lost >10 kg and reached a normal target weight range.

The participants' body and fat composition, glucose tolerance, and blood lipids were assessed at the beginning and end of the research. The volume of visceral adipose tissue (VAT) was initially much larger in the white women than in the African Americans, and white women lost roughly twice as much VAT as African Americans in the course of the study.

Conversely, African American women lost more subcutaneous fat in the diet phase than white women. The post-diet improvement in metabolic profilesfasting insulin levels, concentrations of total cholesterol, HDL cholesterol, and LDL cholesterolwas similar in both races.

The only race-related difference was in concentrations of triacylglycerols, which were initially higher in white women than in African American women and declined at a similar rate. The authors suggest that ethnicity-race may have an effect on triacylglycerol levels that is independent of obesity status.

The differing amounts of visceral weight loss in the two racial groupsand the similar positive effects of weight loss on major disease risk factorsindicate that the healthful benefits of weight loss in premenopausal women cannot be attributed to a particular type of fat deposit.

References: Gower, Barbara A et al. Effects of weight loss on changes in insulin sensitivity and lipid concentrations in premenopausal African American and white women. Am J Clin Nutr 2002:76:923-7.

To see the complete text of this article, please go to: http://www.faseb.org/ajcn/Nov2002/13008.Gower.PDF

Source: American Journal of Clinical Nutrition