To determine the role of FGFR2c in the development of obesity and type 2 diabetes induced by social isolation, we examined the effect of mouse FGFR2-IIIc monoclonal antibody on food intake, body weight changes, epididymal WAT (eWAT), blood glucose, and plasma-free fatty acids and FGF21 levels, and the expression of uncoupling protein-1 (UCP-1), UCP-2 and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α) in the eWAT of individually housed KKAy mice. Here, UCP1 is linked to type 2 diabetes mellitus.