High-monounsaturated fat diet-induced obesity and diabetes in C57BL/6J mice.

A high-monounsaturated fat diet has been proposed as a palatable alternative to a high-carbohydrate diet in diabetic patients, but it is unknown whether a higher intake of monounsaturated fat induces obesity and diabetes, as usually observed with other types of fat. To answer this question, C57BL/6J mice were divided into three groups: the first group was given a high-carbohydrate diet, and the other two groups were given a high-monounsaturated fat diet (60% of total energy) as olive oil or synthetic triolein for 4 months. It has been previously reported that the C57BL/6J mouse has a genetic predisposition for intraabdominal obesity and non-insulin-dependent diabetes mellitus (NIDDM) by high-polyunsaturated fat (n-6) feeding. Although there were no significant differences in energy intake and fat absorption among these three groups, compared with the high-carbohydrate diet, both high-monounsaturated fat diets produced hyperglycemia, obesity, and triglyceride accumulation in the liver and skeletal muscle. These data indicate that the recently recommended high-monounsaturated fat diet might induce obesity and diabetes.