That bagel? It could go right to your gut. Literally. But a bit of olive oil each day may help keep your middle little.

That's what researchers are saying after testing two diets -- one high in carbs and the other based on healthy fats from olive oil. The "fat" diet kept bellies flatter.

Why Belly Fat Is So Bad
Besides making you sad when you zip up your pants, excessive abdominal fat increases your risk for high blood sugar and many other health problems. But in a recent study of overweight people, a Mediterranean-style diet -- where approximately 30 percent to 40 percent of the calories came from unsaturated fats, like those in olive oil -- seemed to help prevent tummy-expanding over time. Another bonus: The fat-focused diet helped people maintain better insulin sensitivity, too. Not so with the high-carb diet, which seemed to encourage body fat to relocate to people’s bellies. (Read this to find out how much Mediterranean eating it takes to reduce heart disease.)

Weight Loss Arithmetic
Keep in mind that extra olive oil isn't going to help you trim your middle. It could just help keep your pants from getting tighter. For serious waist whittling, you'll need two must-do's: a healthy diet and extra exercise. Try the YOU Docs' plan for making this 1+1 waist loss equation work for you.

Did You Know?
Some fats make you hungrier. Get the scoop here on which ones can leave you wanting.