Diet Drinks and Body Weight

Overweight and obese adults who drink diet beverages take in more calories from solid foods—especially snacks—than those who drink sugary beverages, according to a new study. The findings raise questions about using diet drinks for weight control in heavier adults.

Excess weight can raise your risk for many health problems, including type 2 diabetes, cancer, and heart disease. Many people use diet drinks to help control their weight. But studies of how these beverages affect weight control have had mixed results.

To examine the link between diet drinks and calories, NIH-funded scientists looked at data on nearly 24,000 adults. The researchers found that about 10% of healthy-weight adults drank diet beverages, compared to about 20% of over-weight and obese adults.

Healthy-weight adults who drank diet beverages ate less food and fewer total calories on a typical day than those who drank sugared beverages.

Among adults who were over-weight or obese, total calorie intake was similar between those who drank diet or sugary beverages. Heavier adults who drank diet beverages tended to eat more calories in the form of solid foods.

Taking a look at solid-food intake, the scientists found that obese adults who consumed diet drinks ate significantly more calories per day in salty snacks and sweet snacks than those who drank sugared beverages.

“The results 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,” says study coauthor Dr. Sara N. Bleich at the Johns Hopkins Bloomberg School of Public Health.

Future studies might test whether diet drinks help healthy-weight adults maintain their weight.