Fast-Food's Catch? It's Not the Calories

Sure, no one needs the fat and calories in a double cheeseburger with fries. But research suggests it's not the fat and calories you should fear.

It's the impact they have on your opioid receptors. Your what? Your opioid receptors. Animal research suggests that fatty, sugary, high-calorie foods cause weight gain because they stimulate fat-storage genes, which then turns up the inner pound-packing dial. Salad bar, anyone?

Flipping the Fat Switch
Researchers believe kappa opioid receptors play an important role in fat metabolism and that eating foods high in fat and sugar somehow stimulates these receptors not only to promote weight gain but also to store fat in bad places. In the animal study, an unhealthful diet didn't just increase body fat. It encouraged fat storage in the liver, too. And it zapped energy levels. Bottom line: Garbage in means garbage stays -- and makes you tired, too! (Is the needle on your bathroom scale mysteriously creeping higher? Check out four sneaky causes of weight gain you should know about.)

Investigating Fat Genes
More research is needed to determine if the impact fatty foods have on opioid receptors in animals holds true for our bodies, too. But there are a million other reasons to avoid the local drive-through offerings. Next time you get a craving for something oh-so-bad-for-you, try one of these munchie makeovers instead:

• Here are three ways to make a snack more healthful.
• Eat this to stop sugar cravings.
• Discover how to satisfy a craving without gaining weight.

Got a big belly? Brew a fat-busting beverage. This tea helps keep fat cells in line.