Sarcopenia - low skeletal muscle mass and strength - is often found in obese people and older adults; it has been hypothesized that sarcopenia puts individuals at risk for developing Type 2 diabetes.
To gauge the effect of sarcopenia on insulin resistance (the root cause of Type 2 diabetes) and blood glucose levels in both obese and non-obese people, UCLA researchers performed a cross-sectional analysis of data on 14,528 people from the National Health and Nutrition Examination Survey III.
They found that sarcopenia was associated with insulin resistance in both obese and non-obese individuals. It was also associated with high blood-sugar levels in obese people but not in thin people. These associations were stronger in people under age 60, in whom sarcopenia was associated with high levels of blood sugar in both obese and thin people, and with diabetes in obese individuals.
Dieting to be thin is on its own not enough to stave off diabetes. It is also important to be fit and, in particular, to have good muscle mass and strength.