Submitted to: Nutrition Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2016
Publication Date: 6/1/2016
Publication URL: http://handle.nal.usda.gov/10113/62571
Citation: Sundaram, S., Yan, L. 2016. Time-restricted feeding reduces adiposity in mice fed a high-fat diet. Nutrition Research. 36(6):603-611.
Interpretive Summary: Obesity increases the risk of heart diseases, stroke, type 2 diabetes and certain types of cancer. More than one third of the U.S. adults are overweight or obese. Obesity is a result of unbalanced energy metabolism, for example, excessive food intake and lack of physical activity. An important component of energy balance is the coordination of daily rhythm in rest and activity, eating behavior, energy utilization and energy storage over the light/dark cycle. Disruption of the rhythm by eating at the “wrong” time can contribute to obesity. Laboratory rodents with dampened eating rhythms increase food intake and gain body weight. We studied the effects of time-restricted feeding on changes in body fat mass in mice. Unrestricted feeding mice a high-fat diet for both light and dark cycles increased body fat mass. Time-restricted feeding mice the same high-fat diet during the dark cycle (mice are active in dark) did not affect food intake, compared to the unrestricted feeding, but significantly reduced body fat mass. This reduction was accompanied with decreases in blood concentrations of adipose-derived and nutrient sensitive hormones (for example, leptin for the former and insulin for the latter) that contribute to obesity. Our results indicate that it is not the high-fat diet itself but eating at the “wrong” time that contributes to the gaining of fat mass in mice. It suggests that rhythmic timing of food intake may prevent obesity and rectify the metabolic disturbance by a high-fat diet.
Technical Abstract: Disruption of the circadian rhythm contributes to obesity. The present study investigated the effects of time-restricted feeding (TRF) of a high-fat diet on adiposity in male C57BL/6 mice. Three-week-old mice were fed a low-fat or high-fat diet (16% or 45% of energy from corn oil) ad libitum (ad lib) or the high-fat diet restricted to 12 or 8 hours per day during the dark cycle for 11 weeks. Energy intake of TRF 12-hour group was not different from, while that of TRF 8-hour group was slightly but significantly lower than, that of the high-fat ad lib group. Restricted feeding of the high-fat diet significantly reduced body fat mass and body weight compared to mice fed the high-fat diet ad lib. There were no significant differences in respiratory exchange ratio (RER) among TRF and high-fat ad lib groups, but the RER of these groups were significantly lower than the low-fat group. Energy expenditure of the TRF groups was slightly but significantly lower than that of the high-fat ad lib group. Plasma concentrations of ghrelin were significantly increased in TRF groups compared to both low-fat and high-fat ad lib groups. Elevations of plasma concentrations of insulin, leptin, monocyte chemoattractant protein-1 and tissue inhibitor metalloproteinase-1 induced by high-fat ad lib feeding were reduced by TRF to the levels of mice fed the low-fat diet. Our results that TRF during the dark cycle reduces high-fat diet-induced adiposity indicate that circadian timing of food intake may prevent obesity and rectify the metabolic disturbance by a high-fat diet.