With the rapidly rising prevalence of diabetes mellitus worldwide, it is imperative that strategies to prevent the development of diabetes are developed. Individuals at high risk of developing type 2 diabetes should be identified and targeted for prevention. The increased risk for diabetes stems from a combination of genetic predisposition and environmental factors. Although the genetic susceptibility to diabetes remains poorly understood, risk factors such as age, obesity, lifestyle factors including physical inactivity, a Western diet, and smoking, predispose to the development of diabetes. In women, gestational diabetes is another important risk factor for developing diabetes. Individuals with low birth weight at term and those with obstructive sleep apnea have also recently been suggested to have an increased risk.