When we taste something sweet, our bodies prepare to burn calories. But what happens when no calories arrive? This study from Purdue University—the first to test this question—looked at how rats responded to zero-calorie artificial sugar (saccharin).
Your body has a natural response to food that regulates your metabolism. Sweet tastes predict calories, so your body knows to rev up in order to burn them. When those calories don’t come (like with fake sugars), that relationship breaks down. You burn fewer calories and gain more weight.
Worse, fake sugars may actually retrain your body so that you eat more calories and burn fewer no matter what you eat. We may be clever, but we can’t outsmart Mother Nature!