This idea is now supported by the work of Phillip Scherer and colleagues at Albert Einstein College of Medicine, New York, who have shown that insulin resistance in mice is not determined by how fat they are but rather where the fat is stored.
Mice that are obese because they lack leptin (ob/ob mice) become insulin resistant. In the new study, researchers show that if ob/ob mice are engineered to express adiponectin they do not become insulin resistant. However, these mice were morbidly obese and the mass of their fat tissues was much increased compared with normal ob/ob mice. The authors therefore suggest that an inability to maintain high levels of adiponectin might be what causes insulin resistance in individuals who over eat because it would mean that the excess food they consume is stored in regions of the body other than the fat tissues.-Journal of Clinical Investigation
