How Artificial Sweeteners Make You Fat

Rats fed a steady diet of sugar substitutes were hungrier and gained more weight than rats that ate sugary food, a new study has found. The study may explain why people who drink a lot of diet soda have higher rates of obesity, diabetes, and other metabolic problems. Purdue University researchers fed sugar-filled and sugar-free yogurt to groups of rats, and found that rats that got accustomed to artificially sweetened meals were still hungry afterward and went back for more food. Why? It appears that artificial sweeteners confuse the body, which is programmed to associate sweet tastes with calories consumed; when we repeatedly eat something sweet that provides little or no calories, researchers say, we break that connection, and our confused bodies keep seeking more food. Also, the rats that frequently ate sugar substitutes also didn't have the metabolic increase that usually follows eating a meal, so they burned fewer calories, researcher Susan Swithers tells HealthDay. Combine a larger appetitie with a slower metabolism and you have a formula for severe weight gain. "The take-home message," Swithers says, "is that consumption of artificially sweetened products may interfere with an automatic process."