Carrying too many pounds is a solid signal of current or future health problems. But not for everyone. Some people who are overweight or obese mange to escape the usual hazards, at least temporarily. This weight subgroup has even earned its own moniker—metabolically healthy obesity. Most people who are overweight or obese show potentially unhealthy changes in metabolism, like high blood pressure, high cholesterol, and insulin resistance. But some people who are overweight or obese manage to avoid these changes and, at least metabolically, look like individuals with healthy weights. Such individuals have near-normal waist sizes, blood pressure, cholesterol, and blood sugar, as well as good physical fitness. Metabolically healthy obesity isn’t common. And it may not be permanent.

Source: Overweight and healthy: the concept of metabolically healthy obesity