The Effect of Calorie Restriction and Intermittent Fasting on Impaired Cognitive Function in High-Fat Diet-Induced Obesity Started Post-Weaning in Male Wistar Rat

Background: Calorie Restriction (CR) is known as one of the most effective life-extending interventions. Therefore researchers are looking for other interventions or drugs to mimic the mentioned effects. Time-restricted feeding (TRF) has recently gained more attention recently as one of the CR mimetics. Here we evaluate and compare the effects of CR or TRF on cognitive function in young animals fed a high-fat diet (HFD). Methods: This is an experimental study that three-week-old male Wistar rats (n:52) were subjected to a control diet (n:11) or HFD (n:42). Then the HFD group was divided into 1) 30% calorie restriction (CR), 2) Night Intermittent Fasting (NIF), 3) Day Intermittent Fasting (DIF), and 4) Ad-Libitum (AL) with the standard diet for ten weeks (each of 9). An independent T-test or Mann–Whitney test was used for the first phase and in the second phase of the study, one-way analysis of variance (ANOVA), followed by Tukey post-hoc tests, or Kruskal–Wallis and post-hoc Bonferroni test were used. P-values of <0.05 were considered significant. Results: Deteriorated mental function was significantly lower in HFD than CON (p= 0.041). CR was still more efficient than NIF in cognitive function in obese subjects. Post-hoc test indicated that from day 2-4, escape latency was significantly shorter in NIF and CR, which was not seen in other groups (p=0.045). Conclusion: While TRF has garnered much attention recently, here we show that CR is still more efficient in learning and memory tasks. Longer fasting times and different fasting periods are recommended to study.