Type 2 diabetes prevention studies have shown that the onset of the disease can be delayed or prevented, chiefly by weight loss. But the current efforts to establish community-based lifestyle modification programs will not be very effective in preventing diabetes, largely because most overweight or obese people cannot maintain weight loss over time. A complex environment is driving greater food consumption along with less energy expenditure, making maintenance of weight loss extremely difficult. To improve the likelihood of achieving populationwide success in reducing the obesity pandemic, we need a better understanding of the biological processes that underlie the balance between intake and expenditure of energy. In the meantime, once diabetes develops, we can greatly reduce the likelihood of serious complications through early detection and proper medical management.