Newswise — Do diet drinks help or hinder those trying to lose weight? New research from Texas Christian University (TCU) suggests that no-calorie sweeteners may lead to diet-sabotaging choices.
For the study, published this month in the journal Appetite, researchers conducted three experiments in which 116 participants ages 18 to 25 were randomly given an unmarked cup filled with either a non-caloric sweetened beverage (a diet soda), a sugar sweetened beverage (regular soda) or non-sweetened beverage (sparkling water). Researchers then measured their cognition, snack choices and responses to sugary food.
In the first experiment, the diet soda drinkers were faster to identify the names of high-calorie foods (like hamburger or milkshake) than participants who drank a non-sweetened or sugar-sweetened beverage. “There was no difference among the groups in identifying the words of low-calorie foods like ‘apple’ or ‘carrot’,” says study author Sarah Hill, associate professor of psychology at TCU. “It seems that drinking a non-caloric drink may prime you to choose unhealthy food items. Those foods are on your mind.”
In the second experiment, participants – who were told they were taking part in a consumer product study – were given the choice to take home a bag of chocolate candy, a pack of sugar-free gum or a bottle of spring water. The diet soda drinkers were significantly more likely to choose the high-calorie candy than were the participants who had regular soda or sparkling water.
Finally, to test participants’ response to sugar, researchers had the volunteers eat as many cookies as they wanted and then report on their satisfaction. “We found that drinking a diet drink didn’t change how many cookies they ate,” says Hill, “but the participants who had the diet drink did report feeling less satisfied after eating.”
But don’t think sugary beverages get a free pass.
Hill notes that, in the sugar response experiment, there was no difference in the number of cookies eaten by those who drank regular soda and plain water. “People just don’t seem to compensate for the calories consumed in a beverage,” says Hill. “Even if we consciously think about it, a less deliberate part of our mind might not really register those calories.”
“The totality of these studies suggests that drinking artificially sweetened beverages can have unintended consequences and, over time, may influence choices that can affect weight loss goals,” she says.