Can Sugar Substitutes Make You Fat?

In a series of experiments, scientists at Purdue University compared weight gain and eating habits in rats whose diets were supplemented with sweetened food containing either zero-calorie saccharin or sugar. The report, published in Behavioral Neuroscience, presents some counterintuitive findings:

Animals fed with artificially sweetened yogurt over a two-week period consumed more calories and gained more weight — mostly in the form of fat — than animals eating yogurt flavored with glucose, a natural, high-calorie sweetener. It's a continuation of work the Purdue group began in 2004, when they reported that animals consuming saccharin-sweetened liquids and snacks tended to eat more than animals fed high-calorie, sweetened foods. The new study, say the scientists, offers stronger evidence that how we eat may depend on automatic, conditioned responses to food that are beyond our control.