A13158 Intermittent fasting promotes fat oxidation and suppresses of blood glucose and body weight

Abstract

Objectives: Intermittent fasting (IF) has been expected to increase insulin sensitivity and lower blood pressure, without affecting caloric intake. Methods: Mice were subjected to a severe IF regimen, in which they were fasted for 72 hours and then refed ad libitum for subsequent 96 hours. This regimen was consecutively repeated 4 times to enforce the effects. After the 4 courses of the IF regimen, mice were fed a high-fat diet (HFD) ad-libitum for subsequent 4 weeks of observational period. The body weight (BW) was monitored throughout the study period in the IF and ad-libitum feeding groups. Glucose tolerance tests were performed at the 2 different time points: just after 4 courses of the IF regimen and after subsequent 4 weeks of ad-libitum feeding. Results: There was no significant difference in the BW between the adlib eating and IF groups just after the 4 courses of the IF regimen. Glucose tolerance tests showed a significant decrease in the glucose level of IF group. In PCR analysis, expressions of genes responsible for fat oxidation and thermogenesis (ACO, HSL and UCP1 et al.) were significantly increased in the harvested tissues (the skeletal muscle, white and brown adipose tissues). After subsequent 4 weeks of observational feeding period, the BW in IF group was significantly lower than ad-libitum feeding group. At the time-point, the glucose tolerance, respiratory gas and expression of genes maintained the similar changes observed just after 4 courses of the IF regimen. Conclusion: The 72 hours fasting IF regimen resulted in a decrease in the blood glucose level and suppression of the BW under HFD administration. PCR analysis suggested that promotion of fat oxidation and thermogenesis in the skeletal muscle and adipose tissue of the IF group contributed to suppression of blood glucose and BW.