Abstract 1. 1. Adenylate cyclase activity was determined in membranes of white and brown adipose tissue (WAT and BAT, respectively) from rats fed a high-energy diet (EXP group) vs those fed a nutritionally balanced one (CON group). 2. 2. The isoproterenol- and guanine nucleotide-induced adenylate cyclase activity in WAT membranes of EXP rats was lower than that in CON rats. 3. 3. Relative adenylate cyclase activity in like treated BAT membranes was higher in EXP than in CON rats. 4. 4. It is concluded that feeding high-energy diets to rats induces similar post-receptor modifications of adenylate cyclase as found in genetic obese rodents.