Are you thin on the outside and obese on the inside? The superfat phenomenon...

You can’t always judge a book by the cover. And the same goes for fat. 

According to Dr. Jimmy Bell, a professor of molecular imaging at the Imperial College at the University of London, skinny people—even supermodel types—can be superfat. He says it can be a shock when a thin person has as much internal body fat as an obese or even morbidly obese person. As many as 30 million Americans may fall into this normal-weight but obese on the inside category.

Internal fat is typically found from the top of your hips to the top of your liver and hidden around organs. Dr. Bell says the more internal body fat a person has, the more they are setting themselves up for health problems later. A thin but overfat person without health problems can reach a tipping point and develop high blood pressure or Type 2 diabetes.

If you’re slim but not very active, you need to get moving to lose that internal fat. Find a way to work some cardio exercise into your life four to five days a week.