# Time‐Restricted Access to High‐Fat Diet Influences Weight Gain, Meal Patterns, and Food Preference

## TL;DR

Restricting high-fat diet access to the light or dark cycle in mice leads to different weight gain and eating patterns.

## Contribution

The study shows that timing of high-fat diet access affects weight gain and food preference in mice.

## Key findings

- Light cycle HFD access increases weight and fat mass gain despite equal daily caloric intake.
- Dark cycle HFD access reduces weight gain and promotes chow preference.
- Light cycle HFD access mimics the negative effects of unrestricted high-fat diet.

## Abstract

Access to only high‐fat diet (HFD) during the light versus dark cycle promotes different metabolic outcomes. We assessed changes in body weight/composition, feeding behavior, and metabolic parameters in mice fed HFD during the light or dark cycle with concomitant ad libitum access to chow.

Male C57BL/6J mice were housed in metabolic chambers with two hoppers containing chow. HFD was then provided in one hopper, with access restricted to the light or dark cycle. The other hopper provided ad libitum access to chow. Food intake, meal patterns, energy expenditure, activity, and substrate oxidation were measured for ~4 weeks. Body weight/composition was measured before and after ~4‐week HFD access.

Light cycle HFD access promoted greater weight and fat mass gain. Although daily caloric intake was equivalent between groups, light cycle HFD access increased preference for HFD and intake of larger, more frequent HFD meals during the daytime. Dark cycle HFD access promoted preference for chow and consumption of larger, more frequent chow meals.

Light cycle HFD access parallels detrimental metabolic outcomes of ad libitum HFD access. Dark cycle HFD access reduces weight gain and adiposity; this is associated with enhanced chow preference.