Effects of energy or protein restriction on weight and composition of diabetic and control rats

Adult (170 ± 1 g) male Sprague-Dawley diabetic (50 mg/kg of streptozotocin) and control rats were fed for 21 days a diet with adequate protein (28%) at three restricted levels of intake (34, 45 or 57 kcal/day), or were fed at a single level of intake (ad libitum) diets containing different percentages of protein (2.25, 5.5 and 11.1). When dietary protein was adequate (28%), but energy intake was severely restricted (34 kcal/day), diabetic and control rats lost 80 ± 5 and 100 ± 6 g/kg ^0.75 in body weight, respectively. Diabetic and control rats lost 110 ± 4 and 139 ± 7 g/kg ^0.75 in body weight, respectively, when energy was unrestricted and dietary protein was at a submaintenance level (2.25%). Body weight of diabetic and control rats did not differ when dietary protein was adequate (28%) and energy intake was moderately restricted (45 kcal/day) or when energy intake was unrestricted and dietary protein was at a maintenance level (5.5%). This study showed that diabetic rats fared as well as or better than their control counterparts when the intake of either energy or protein was moderately or severely restricted.