True or false: You can have a normal weight and BMI and still be "obese."

It's true. Even if you're no bigger than a minute, you could still be at risk for cardiovascular disease and metabolic syndrome if your fat mass is greater than 30 percent of your body weight. It's called "normal-weight obese syndrome." Here's how it works.

Overall weight and BMI are a good start when estimating health risks, but they don't tell the whole story. What's more important is how much fat you have relative to your overall weight and where that fat is on your body.

The higher your percentage of fat mass -- and the more fat you have bunched around your middle -- the more proinflammatory cytokines you have racing around in your blood. What's so bad about that, you ask? These chemicals signal inflammation, and the more inflammation you have in your body, the greater your health risks. Cytokines also affect the way your body uses insulin and contribute to hardening of the arteries.

Once the inflammation ball gets rolling, your risk of obesity, cardiovascular disease, and metabolic syndrome go up. Which helps explain, in part, why skinny people can still get heart disease and may pack on pounds after a certain age.

To lower your percentage of body fat, use the triple threat: cardiovascular exercise, weight training, and a balanced diet. No time to exercise? Use these double-duty moves that blend exercise with everyday activities.

And don't throw out your scale or ignore your BMI altogether. They still provide important information about your overall health. Check your BMI and waist-to-height ratio with this online tool.

Get your waist back! Try YOU: On a Diet, a realistic waist-management plan from RealAge Drs. Mehmet Oz and Michael Roizen.