
The study employed a prospective, randomized clinical trial to directly compare the effects of water and diet beverages on weight loss. The 303 participants in the study all took part in a behavioral weight loss program in which each followed an identical diet and exercise program. However, during the 12-week duration, half of the group consumed diet beverages made with non-nutritive sweeteners (NNS), such as diet sodas, teas and flavored waters. The other half drank water only, but were allow to consume foods made with sugar substitutes, such as artificially-sweetened yogurt, gum, candies, cookies, ice cream, gelatin, pudding), but could not intentionally add NNS like aspartame, sucralose or stevia to beverages.
Researchers found that subjects who consumed diet beverages lost an average of 13 pounds, whereas the control group (those that only drank water) lost an average of 9 pounds. Moreover, 64 percent of the participants in the diet beverage group lost at least 5 percent of their body weight, compared with only 43 percent of the control group. While both diet soda and water groups saw reductions in waist circumference, and blood pressure, those that consumed diet sodas also reported “feeling significantly less hungry” than the ones in the water group.
The results come four months after the findings of a recent study conducted by researchers at the Johns Hopkins Bloomberg School of Public Health, which surmised that consumers who drink diet sodas might actually end up gaining weight.