Which factor is most associated with the incidence of Type 2 diabetes mellitus?

Overweight is the most significant factor associated with the incidence of Type 2 diabetes mellitus. This condition is closely linked to obesity due to its impact on insulin resistance. When an individual is overweight, especially with excess fat accumulated around the abdomen, the body's cells can become less responsive to insulin, leading to higher blood glucose levels. This resistance interferes with the normal function of insulin, which is essential for regulating blood sugar.

While genetic predisposition, stress levels, and age can contribute to the risk of developing Type 2 diabetes, they do not have as direct and strong an association as being overweight. Genetics play a role in determining an individual's risk but cannot be altered. Stress can influence lifestyle choices that may lead to poor dietary habits and inactivity, contributing indirectly to obesity, which is the primary risk factor. Age does increase the risk, but its impact is often mediated through changes in body weight and lifestyle that typically occur as people get older. Therefore, among these options, being overweight stands out as the most critical and modifiable risk factor in the incidence of Type 2 diabetes.