Obesity and type 2 diabetes are metabolic disorders that have strong associations with body composition.
The metabolic perturbations that characterize type 2, those of:
elevated fasting insulin,
increased fatty acids and triglycerides,
and, most fundamentally, insulin resistance,
have been found to be associated with adiposity and perhaps, more particularly, with certain patterns of adipose tissue and fat distribution.
Insulin resistance is a principal mechanism by which obesity is considered to heighten risk of type 2 diabetes.
In obesity, there is insulin resistancein adipose tissue and muscle.
Weight change (gain vs. loss or stabilization) has been found to influence risk for development of type 2 diabetes in both men and women.
In several investigations of older adults, including large population studies, neither the amount of fat-free mass nor the amount of skeletal muscle was associated with insulin resistance or type 2 diabetes.
Obese individuals are insulin resistant after adjustment for fat-free mass.
However, the quality rather than the quantity of fat-free mass has been found to be a very important body composition consideration in insulin resistance, obesity, and type 2 diabetes.