CHAMPAIGN, Ill., Sept. 11 (UPI) -- Drinkers of diet beverages were found to obtain more of their daily caloric intake from discretionary "junk" foods, likely canceling out the benefits of lower-calorie drinks, according to a new study.
Nearly all of the participants in a large review of nutrition data at the University of Illinois consumed discretionary foods, though researchers said the explanation for some consumers of diet drinks may be tied to guilt for other eating habits.
Discretionary foods are foods that do not belong to the major food groups and are not essential to the human diet, including things like french fries, cookies, ice cream, chocolate and pastries.
"If people simply substitute diet beverages for sugar-sweetened beverages, it may not have the intended effect because they may just eat those calories rather than drink them," said Ruopeng An, a professor of kinesiology and community health at the University of Illinois, in a press release.
An reviewed data on the dietary habits of 22,513 people collected between 2003 and 2012 as part of the National Health and Nutrition Examination Survey, comparing people's daily caloric intakes from discretionary foods and 5 types of beverages -- diet or sugar-free drinks, sugar-sweetened beverages, coffee, tea, and alcohol.
More than 90 percent of the survey participants consumed discretionary foods every day, gaining about 482 calories from the on average, while 97 percent of people drank at least 1 of the 5 beverage types every day. In addition, 41 percent consumed at least 2 of the drinks each day and 25 percent had 3 per day.
Among the participants, 53 percent drank coffee -- by far the highest proportion of any of the beverages -- while 43 percent drank sugar-sweetened beverages such as soda and juice, 26 percent drank tea, 22 percent drank alcohol, and 21 percent prefer diet beverages. In terms of caloric intake, the largest daily increase was caused by alcohol consumption, followed by sugar-sweetened beverages, coffee, diet beverages, and tea.
Participants who drank coffee and diet beverages were found to obtain a higher percentage of daily calories from discretionary foods. However, among obese adults, as well as those with the most income and education, diet beverages were most linked with increased caloric intake.
Coffee drinkers were also among people with the worst dietary habits, but researchers suggest that many people opting for diet drinks were in fact compensating for the lower caloric intake in the beverage. One suggestion put forward by researchers is that the choice of a diet beverage was meant to balance out other poor eating habits.
An said it's possible people who drink diet beverages feel justified in eating more, "so they reach for a muffin or bag of chips." He added that it could also be that the lower calorie drink leaves them feeling less full, leading to a desire for more food.
"We'd recommend that people carefully document their caloric intake from both beverages and discretionary foods because both of these add calories -- and possibly weight -- to the body," An said.