Lead author Sara Bleich, an associate professor at The Johns Hopkins Bloomberg School of Public Health's Department of Health Policy and Management, and colleagues say they used data from the 1999 to 2010 National Health and Nutrition Examination Survey.
The researchers looked at national patterns in adult diet beverage consumption and caloric intake by body-weight status. The study finds U.S. consumption of diet soda increased from 3 percent to 20 percent today.
Individuals who drink diet soda typically have a higher body mass index and consume more snack food than those who drink sugary beverages, the study says.
Earlier research may explain why the investigators found higher consumption of solid food among heavy adults who drink diet beverages. Artificial sweeteners, present in high doses in diet soda, are associated with a greater activation of reward centers in the brain, thus altering the reward a person experiences from sweet tastes, Bleich says.
In other words, among people who drink diet soda, the brain's sweet sensors may no longer provide a reliable gauge of energy consumption because the artificial sweetener disrupts appetite control. As a result, consumption of diet drinks may result in increased food intake overall, the study says.
"The results of our study suggest that overweight and obese adults looking to lose or maintain their weight -- who have already made the switch from sugary to diet beverages -- may need to look carefully at other components of their solid-food diet, particularly sweet snacks, to potentially identify areas for modification," Bleich says in a statement.
The study is published the American Journal of Public Health.