Purpose of reviewPatients with type 1 diabetes (T1D) are typically viewed as lean individuals. However, recent reports showed that their obesity rate surpassed that of the general population. Patients with T1D who show clinical signs of type 2 diabetes such as obesity and insulin resistance are considered to have “double diabetes.” This review explains the mechanisms of weight gain in patients with T1D and how to manage it.Recent findingsWeight management in T1D can be successfully achieved in real-world clinical practice.SummaryNutrition therapy includes reducing energy intake and providing a structured nutrition plan that is lower in carbohydrates and glycemic index and higher in fiber and lean protein. The exercise plan should include combination stretching as well as aerobic and resistance exercises to maintain muscle mass. Dynamic adjustment of insulin doses is necessary during weight management. Addition of anti-obesity medications may be considered. If medical weight reduction is not achieved, bariatric surgery may also be considered.

In comparison to standard care, patients with T1D and obesity who participated in an IMWM programme achieved significant weight loss and significant reduction in daily insulin dose at 1 year. Weight reduction was associated with improvements in glycaemic control compared to baseline.