Background: People with autoimmune diabetes require lifelong treatment with subcutaneous insulin, are exposed to glycemic excursions and may frequently need defensive carbohydrate intake, all conditions potentially impacting on adipose tissue accumulation and distribution. Thus, we hypothesized that body mass composition may differ between people with and without autoimmune diabetes on exogenous insulin therapy. Aim and Methods To compare body fat distribution between people with and without autoimmune diabetes, we studied body mass composition by DXA in 27 adults (17 females, median [interquartile range] age: 52 [28] years; body mass index (BMI): 25.7 [5.3] kg/m2) with autoimmune diabetes on insulin therapy for >1 year, and in 28 age, sex- and BMI-matched healthy controls. Adiponectin and leptin levels were also measured. Differences between groups were tested by fitting linear regression models accounting for age, gender, and BMI as confounders. Results: People with and without autoimmune diabetes had a similar amount and percentage of total body fat (21.1 [12.6] Kg vs 18.9 [14.2] Kg, p=0.69; 26.1 [12.5]% vs 27.2 [13.7]%, p=0.083) and of total lean mass (47.8 [21.2] Kg vs 47.1 [16.3] Kg, p=0.35; 73.9 [12.0]% vs 72.9 [13.7]%, p=0.10). Nonetheless, compared to healthy controls, people with autoimmune diabetes showed lower trunk-to-appendicular fat ratio (0.71 [0.46] vs 0.92 [0.46], p=0.027), and lower amount of visceral adipose tissue (264 [315] vs 335 [253] g, p=0.010). Accordingly, adiponectin-to-leptin ratio was higher among cases than among controls (1.2 [1.9] vs 0.7 [0.8], p=0.009). Conclusions: Our data show that people with autoimmune diabetes have healthier body mass composition compared to controls, as highlighted by better ectopic fat deposition indexes and adipokines profile. These results suggest that the physiology of adipose tissue, at least concerned in the deposition of fat, is different in people with autoimmune diabetes, therefore deserving ad hoc studies. Whether and to what extent the differences we found impact the cardiometabolic risk of people with autoimmune diabetes should also be uncovered.