Study Suggests Diet Sodas May Contribute To More Belly Fat In Older Adults

A new study published in the Journal of the American Geriatrics Society found that older adults who drank diet soda gained nearly three times as much belly fat as nondrinkers. The study examined data taken periodically for nine years from 749 Mexican-Americans and European-Americans who were 65 or older.

Over those nine years, the waist size of the study participants who didn't drink any soda increased by 0.8" on average. The average increase was 1.83" among those who drank diet soda occasionally, and 3.16" for those who drank it daily.

Increased belly fat, which is usually what adds to waist circumference, may raise people's risk of cardiovascular disease and other health issues because it causes inflammation, according to Sharon Fowler, an adjunct assistant professor in the Department of Medicine at the University of Texas Health Science Center in San Antonio and lead author of the study.

"We're being naive if we only look at the number of calories in the label. People may be sabotaging their own health if they use diet sodas to protect themselves from gaining weight," Fowler said.

The researchers said that it is not clear exactly why drinking diet soda may be linked to an increase in belly bulge, but the cause may be associated with the artificial sweeteners used in diet soda, and the way they might affect food-intake regulation. The sweeteners could boost weight gain by disrupting the way the body processes sugar, making people hungrier, according to Fowler.

It's also possible that diet sodas are not causing the weight gain. One possibility is that the study participants may have gained weight over the past several years and turned to diet soda to lose weight, but then still kept putting on pounds because of other dietary habits. Another possibility is that people use diet sodas as an excuse to eat more of other high-calorie foods, Fowler said.

In a statement, the American Beverage Association said that numerous studies have repeatedly demonstrated the benefits of diet beverages and low-calorie sweeteners in helping to reduce caloric intake.

The Calorie Control Council, which represents producers of no- and low-calorie foods and beverages, also urged that the study be treated with caution. It pointed out that older people tend to lose muscle mass and gain waist circumference as a result of aging and that some important information on Mexican-American lifestyles, diet records and family histories were not available to the researchers.

JAGS's study is titled "Diet Soda Intake Is Associated with Long-Term Increases in Waist Circumference in a Biethnic Cohort of Older Adults: The San Antonio Longitudinal Study of Aging (SALSA)." Check out the abstract.