Dietary therapy approaches for diabetes: role of patient characteristics and vegetable intake

Type 2 diabetes (T2DM) is a metabolic disorder caused by insulin deficiency. The pathogenesis of T2DM consists of impaired insulin secretion from pancreatic islets and insulin resistance. At present, it is thought that impaired insulin secretion mainly contributes to the pathogenesis of T2DM in Japanese individuals. However, insulin resistance clearly underlies the prevalence of T2DM in Japan as well as in Western countries. This is due to the Westernization of Japanese lifestyles, resulting in the increased prevalence of visceral obesity. Dietary therapy is a fundamental treatment for T2DM, and aims to ameliorate obesity and improve insulin resistance. On the other hand, the aging population with T2DM is increasing in Japan. In elderly patients, dietary therapy should focus on the prevention of frailty due to sarcopenia. Therefore, a uniform approach to nutritional goals is challenging in light of the diverse characteristics of T2DM. Several investigations have confirmed an association between the consumption of vegetables and the risk of T2DM. Recent research revealed that increased vegetable intake contributes to improved control of blood glucose levels and a decreased incidence of cardiovascular disease in T2DM. However, the consumption of vegetables is decreasing in Japan, possibly due to the rapid change in eating patterns of younger generations.