Effect of abrupt and gradual calorie restriction regimens on biochemical and behavioral markers in obese mice model.

Although Calorie Restriction (CR) is primarily considered in obesity management, behavioral studies of CR and its methodology of implementation are not well-defined. The study aimed to determine the efficacy of the extensively researched method of CR-abrupt calorie restriction (ACR) and a newly proposed gradual calorie restriction (GCR) in terms of body weight, behavioral and biochemical parameters in the obese animal model-C57BL/6J mice. Male obese mice were subjected to GCR regimen for 14 weeks which was compared and evaluated for anxiety-like behavior and stress levels with ACR. Plasma corticosterone was measured before initiation of CR and every three weeks following GCR and ACR, whereas plasma insulin was measured twice-after obesity induction and post 14 weeks of CR. The behavioral assessments were conducted before inducing CR and every three weeks following ACR and GCR. A significant anxiety-like behavior and an increase in plasma corticosterone were observed in mice on GCR during the critical initial six weeks of CR ( < 0.05). Both groups showed a decrease in plasma glucose levels; however, the GCR group showed a significant reduction ( < 0.01). There was a significant decrease in social interaction in both groups with an increase in the latency period and a decrease in time spent with the stranger animal during the social interaction test ( < 0.05). The mice on GCR regimen demonstrated lesser anxiety-like behavior and low plasma corticosterone levels compared to those on ACR. This gives us a new avenue in CR research to evaluate the methodologies of implementing CR.