ZF rat study: long-term efficacy (A–D) and side effects (E–H). For all groups, the insulin resistance index (B) was assessed after 43 d of drug treatment whereas all other parameters (A, C–H) were assessed after 50 d of drug treatment. ZL, Vehicle-treated ZL rats; ZF, vehicle-treated ZF rats; EWAT, epididymal white adipose tissue, IBAT, intrascapular Brown adipose tissue. Values are mean ± sem (n = 6–8/group; *, P < 0.05; **, P < 0.01; ***, P < 0.001 vs. ZF vehicle, one-way ANOVA and Dunnett’s multiple comparison test).