Time-restricted feeding of a high-fat diet reduces diet-induced obesity

Authors: Sundaram, Sneha; Yan, Lin

Submitted to: Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2015
Publication Date: 5/31/2015
Citation: Sundaram, S., Yan, L. 2015. Time-restricted feeding of a high-fat diet reduces diet-induced obesity [abstract]. Canadian Nutrition Society, Lipid Nutrition and Metabolism in Human Health Workshop Proceedings. 28.

Interpretive Summary: Reducing obesity may alleviate many medical complications including diabetes, cardiovascular disease and cancer. It has been suggested that obesity is contributed by the disruption of the circadian rhythms in addition to increased caloric intake. Restricting feeding to particular times of the day may reset the circadian rhythms and is expected to reduce obesity and resulting complications. This study determined the effects of time-restricted feeding (TRF) of a high-fat diet on diet-induced obesity in male C57BL/6 mice. Mice were fed a low-fat (16% of energy from fat) or high-fat diet (45% of energy from fat) ad lib or high-fat diet restricted for 8 hrs or 12 hrs during the dark cycle for 11 weeks. Restricted feeding (8hrs and 12 hrs) of the high-fat diet significantly reduced body weight and body fat mass compared to mice fed the high-fat diet ad lib; there were no significant differences in absolute lean mass weights among all treatment groups. There was no significant difference in caloric intake between TRF 12 hrs group and the high-fat ad lib group; however, the intakes of both of these groups were marginally but significantly higher than that of TRF 8 hrs group. Metabolic measurements (Oxymax Comprehensive Lab Animal Monitoring System, CLAMS) showed that Respiratory exchange rates (RER) and total activity rates were not significantly different among TRF and ad lib high-fat diet fed groups. Both RER and movement of the TRF groups were elevated during the feeding period in the dark cycle compared to the high-fat ad lib group that showed consistently elevated RER and movement throughout both light and dark cycles. Similarly, total energy expenditure was not significantly different among either the TRF groups or the high-fat ad lib group indicating that energy expenditure does not contribute to the reduction of obesity in TRF groups. Taken together, our findings showed that consumption of a high-fat diet led to obesity and TRF reduced such an obesogenic process. The mechanisms of which need to be further elucidated; however time-restricted feeding may be promising in obesity prevention.

Technical Abstract: Reducing obesity may alleviate many medical complications including diabetes, cardiovascular disease and cancer. It has been suggested that obesity is contributed by the disruption of the circadian rhythms in addition to increased caloric intake. Restricting feeding to particular times of the day may reset the circadian rhythms and is expected to reduce obesity and resulting complications. This study determined the effects of time-restricted feeding (TRF) of a high-fat diet on diet-induced obesity in male C57BL/6 mice. Mice were fed a low-fat (16% of energy from fat) or high-fat diet (45% of energy from fat) ad lib or high-fat diet restricted for 8 hrs or 12 hrs during the dark cycle for 11 weeks. Restricted feeding (8hrs and 12 hrs) of the high-fat diet significantly reduced body weight and body fat mass compared to mice fed the high-fat diet ad lib; there were no significant differences in absolute lean mass weights among all treatment groups. There was no significant difference in caloric intake between TRF 12 hrs group and the high-fat ad lib group; however, the intakes of both of these groups were marginally but significantly higher than that of TRF 8 hrs group. Metabolic measurements (Oxymax Comprehensive Lab Animal Monitoring System, CLAMS) showed that Respiratory exchange rates (RER) and total activity rates were not significantly different among TRF and ad lib high-fat diet fed groups. Both RER and movement of the TRF groups were elevated during the feeding period in the dark cycle compared to the high-fat ad lib group that showed consistently elevated RER and movement throughout both light and dark cycles. Similarly, total energy expenditure was not significantly different among either the TRF groups or the high-fat ad lib group indicating that energy expenditure does not contribute to the reduction of obesity in TRF groups. Taken together, our findings showed that consumption of a high-fat diet led to obesity and TRF reduced such an obesogenic process. The mechanisms of which need to be further elucidated; however time-restricted feeding may be promising in obesity prevention.