Lifestyle-related diseases like diabetes and metabolic syndrome develop with various genetic predispositions, combined with environmental factors. For example, the sharp increase in the number of diabetes patients in Japan is assumed to be due to lower insulin secretory capacity of pancreatic beta cells in Japanese as compared to Westerners (genetic predisposition), and the fact that pancreatic beta cells do not fully compensate for insulin-resistant conditions like westernized high-fat diets and reduced physical activity (environmental factors). This project involves research on the interaction of genetic and environmental factors in lifestyle-related diseases (e.g. metabolic syndrome, obesity, diabetes), aimed at exploring the causes and pathophysiology of these diseases.