[Obesity disease with diabetes mellitus]

Obesity has been increasing not only in Japan but also in both developed and developing countries. Mean body mass index of Japanese patients with type 2 diabetes has been increasing, and it reached 25.0 in 2013. If body weight decreases more than 3% of initial body weight in patients with metabolic syndrome, not only glucose metabolism but also dyslipidemia and hypertension improve. To reduce the excess body weight, behavior therapy, calorie restriction, and exercise are necessary. The next strategies are drugs including mazindol, glucose-like peptide-1 receptor agonist and sodium-dependent glucose cotransporter 2 inhibitor, and bariatric surgery. Because it is often difficult to reduce body weight using only present non-invasive therapies, clarification of appetite mechanisms and development of novel anti-obesity drugs with few side effects are needed.