Not all obese individuals suffer from high blood pressure, diabetes, or other metabolic disorders and now scientists explain why. Time reports on a study in Diabetologia that examined the metabolic profiles of sets of twins in which one twin was obese and the other was not. On average, the obese twin was about 38 pounds heavier than the non-obese twin. Scientists examined metabolic health of the twins by looking at “subcutaneous, intra-abdominal and liver fat” and using a oral glucose tolerance test (OGTT) for glucose levels and insulin sensitivity. Researchers found that among twins, the differences in glucose levels and insulin sensitivity was not dependent on weight, but rather was dependent on liver fat percentage. Only in sets of twins in which liver fat percentage differed were there poor OGTT results, in the form of insulin resistance, obtained for the obese twin.