Q & A
Q: Does drinking diet soda cause weight gain?
A: No. In fact, diet sodas, which are 99 percent water, have been proven to be an effective tool for weight loss and weight maintenance.
When it comes to obesity, all calories count, regardless of their source. Science has shown that the key to maintaining a healthy weight is energy balance, that is balancing calories consumed with calories burned. Many people trying to lose weight often switch to diet beverages that contain low-calorie sweeteners as a way to reduce their caloric intake.
According to the American Diabetes Association and the Academy of Nutrition and Dietetics (formerly the American Dietetic Association), low-calorie sweeteners can help reduce calories and sugar intake and aid in maintaining a healthy weight.
Source: De La Hunty, A., Gibson, S. and Ashwell, M. (2006), A review of the effectiveness of aspartame in helping with weight control. Nutrition Bulletin, 31: 115–128;
American Diabetes Association
Phelan S, Lang W, Jordan D, Wing RR. Use of artificial sweeteners and fat-modified foods in weight loss maintainers and always-normal weight individuals. Int J Obes (Lond). 2009 Oct;33(10):1183-90.
Academy of Nutrition and Dietetics