Overweight and obese adults who drink diet pop also tend to eat more calories each day from food, a finding that hints at how relying on diet beverages for weight loss could be a mistake.
In this week’s issue of the American Journal of Public Health, researchers from Johns Hopkins Bloomberg School of Public Health in Baltimore analyzed U.S. survey data for 24,000 people from 1999 to 2010. They looked for patterns in beverage consumption and calories.
Overweight consumers of diet beverages took in 1,965 in food calories a day compared with 1,874 calories among those in the same weight class who drank beverages sweetened with sugar, such as non-diet soda, sports drinks, fruit drinks and sweetened tea.
As people increasingly switch to diet beverages, the focus on reducing sugar from drinks might not be enough to lose weight in the long term, the researchers concluded.
"The switch from a sugary beverage to a diet beverage should be coupled with other changes in the diet, particularly reducing snacks," suggested lead author Sara Bleich.
In the study, snacking patterns were generally the same between diet and sugary beverage drinkers. The researchers said the finding is consistent with evidence that the sweet taste of beverages, whether from sugar or artificial sweeteners, enhances our appetite and encourage cravings for sugar.
Dana Small, a professor of psychological sciences at Yale University in New Haven, Conn., was not involved in the study. Small suspects that since sweet tastes no longer guarantee calories, taste preferences could shift toward higher calorie, sweeter foods.
Kelly Brownell, a professor of psychology and neuroscience at Duke University in Durham, N.C., called the findings compelling but cautioned that "people need to separate the biology from the psychology."
The study can’t prove that drinking low-calorie beverages increases calorie intake, the researchers said. They also acknowledged that the 24-hour, self-reported food and beverage intake may not accurately reflect how much people consume.
In a statement, the American Beverage Association, a trade group, said diet beverages have been shown to be an effective tool as part of an overall weight management plan.