Sugar Substitutes May Distort the Body's Natural Calorie Counter
June 30, 2004 -- Sugar substitutes may offer sweet treats for calorie-conscious dieters, but a new study shows that they may also play tricks on the body and sabotage weight-loss efforts.
Researchers say artificial sweeteners may interfere with the body's natural ability to count calories based on a food's sweetness and make people prone to overindulging in other sweet foods and beverages.
For example, drinking a diet soft drink rather than a sugary one at lunch may reduce the calorie count of the meal, but it may trick the body into thinking that other sweet items don't have as many calories either.
Researchers say the findings show that losing the ability to judge a food's calorie content based on its sweetness may be contributing to the dramatic rise in overweight and obesity rates in the U.S.
But don't ditch your diet drink yet.
"The message is not to give up your diet soda and go drink a regular soda," says researcher Susan Swithers, PhD, associate professor of psychological sciences at Purdue University. "But when you do drink beverages you probably need to pay a little more attention to whether they have calories or not and what the consequences of that fact will be on the rest of your diet."
Sweetness Provides Calorie-Counting Clues
Swithers says that in the past, a food's sweetness provided valuable clues about its caloric content, and something sweet was usually a good source of energy.
"Before things like artificial sweeteners, these relationships would be very reliable," says Swithers. "Animals needed to find good sources of calories and needed to know whether eating something provided them with lots of calories."
"It's only been relatively recently that foods have been introduced that violate those kind of relationships, such as something very sweet that has no calories," Swithers tells WebMD.
According to researchers, the number of Americans who consume sugar-free, artificially sweetened products has grown from less than 70 million in 1987 to more than 160 million in 2000.
At the same time that more people are drinking and eating foods sweetened with low-calorie sweeteners, such as aspartame and saccharin, they're not getting any thinner. In contrast, more people are becoming overweight or obese.
That prompted researchers to test whether not being able to use sensory clues to predict the calorie content of foods might contribute to overeating and weight gain.