The ability to regulate energy level by male albino rats on administration of food with varying caloric densities, was studied. The animals fed different caloric density diets exhibited marked variations in their caloric in take in the initial stages which stabilized after 5 to 10 days and maintained on lower mean caloric intake on diet having density of 2.63 Kcal/gm, and higher mean caloric intake on diet with density of 4.88 Kcal/gm. Similar variations in body weight were also evident with failure to maintain the body weight with caloric dilution.