The Wenzhou Gestational Diabetes Cohort (WGDC) is a prospective cohort study among women with gestational diabetes mellitus (GDM) during pregnancy and their offspring living in Wenzhou, China. The primary aim of this cohort is to characterize the continuous blood glucose response to dietary intake and physical activity among pregnant women with GDM over 2 weeks, and to facilitate the development of personalized nutritional/lifestyle recommendation among these patients. Another aim of the WGDC is to investigate the association of dietary and physical activity together with continuous glucose change during pregnancy on the adverse birth outcomes including preterm birth, macrosomia and large-for-gestational-age birth. The secondary aim is to investigate the prospective associations of diet, physical activity and continuous glucose change over 2 weeks among the patients with long-term metabolic health of the women and their offspring.