Final answer:
The dramatic increase in type 2 diabetes cases over the past two decades is largely due to rising obesity rates. This condition, often associated with insulin resistance, is now being diagnosed at younger ages, including in children, because of lifestyle and dietary factors.
Step-by-step explanation:
The most dramatic increase in the incidence of type 2 diabetes over the past two decades has primarily involved populations that are experiencing higher rates of obesity. Obesity is a significant risk factor for developing type 2 diabetes, contributing to increased insulin resistance. Insulin resistance is a condition where cells in the body become less responsive to insulin, thereby leading to high blood glucose levels. Type 2 diabetes used to be diagnosed typically after the age of 40, but with the recent rise in obesity among younger populations, including children and adolescents, the age of onset has decreased. Lifestyle modifications, including achieving a healthy weight, increasing physical activity, and consuming a nutritious diet, can effectively manage and sometimes reverse type 2 diabetes. When blood glucose levels cannot be controlled through these measures alone, medication or insulin injections may become necessary.