Over the past 25 years, the prevalence and incidence of type 2 diabetes have increased alarmingly worldwide and across all age, gender, and race/ethnic groups. The high economic costs, resulting from the numerous and severe complications of this disease, as well as the social burden associated with diabetes mellitus, have motivated the pursuit of prevention methods. Recently, clinical and observational studies have demonstrated the adverse effects of obesity and sedentary lifestyle, as well as the benefits of moderate weight loss and related behaviors, including increased levels of physical activity, in maintaining metabolic control and reducing the incidence of type 2 diabetes. The challenge remains to find ways to successfully deliver this message to the communities, and to evaluate the cost-effectiveness of the different delivery approaches.