Rat Study Links No-Calorie Sweeteners, Weight Gain
Animals taught to disconnect sweet taste and calories ate more and gained more weight
MONDAY, Feb. 11 (HealthDay News) -- Rats that ate food containing non-caloric sweetener gained more body weight, had less tendency to later compensate for a high-calorie meal, and showed less thermic response to a sweet-tasting food, compared to rats that ate food sweetened with glucose, according to research published online Feb. 10 in the journal Behavioral Neuroscience.
Susan E. Swithers, Ph.D., and Terry L. Davidson, Ph.D., of Purdue University in West Lafayette, Ind., conducted three experiments with male Sprague-Dawley rats. All involved feeding rats yogurt either sweetened with glucose (in which sweet taste predicted higher calories) or saccharin, interspersed with days of unsweetened yogurt. In experiments 2 and 3, rats were then given a novel sweetened food, followed by rat chow; rats had implanted temperature transmitters in experiment 3.
Rats in the saccharin group showed greater adiposity; they ate more chow even after a sweet novel meal, thus demonstrating lack of caloric compensation; and they had a smaller increment in core body temperature after eating a novel sweetened high-calorie food. This points to the possibility that human use of non-caloric sweeteners could promote more eating and weight gain.
"It is conceivable that just as exposure to non-predictive sweet taste-calorie relationships in the laboratory appears to promote increased body weight and body adiposity in rats, the widespread use of non-caloric sweeteners in the food environment of humans may have similar effects on the predictive validity of sweet tastes and ultimately on the normal ability of humans to control their intake and body weight," the authors conclude.