TOPLINE:

Restricting access to a high-fat diet (HFD) in mice to either their active or inactive period promoted vastly different effects on their food preference and meal patterns that parallel behaviors observed in humans with dysregulated sleep-wake cycles.

METHODOLOGY:

• Researchers wanted to determine whether restricting access to an HFD in mice to their inactive period (when it’s light) or active period (when it’s dark) might produce different effects on weight, eating behavior, and metabolic patterns like those seen in humans with dysregulated sleep-wake cycles, such as night shift workers.
• They randomly assigned 16 male mice to one of two groups: the light-cycle group or the dark-cycle group. The mice, studied between 10 and 12 weeks of age, were housed individually in metabolic chambers.
• Mice in the light-cycle group had access to a 60% HFD only during the light cycle, while mice in the dark-cycle group had access to the HFD only during the dark cycle. Both groups had continuous access to low-fat chow, and the location of the food hoppers was switched every 4 days.
• The study lasted 27 days, with food intake, locomotor activity, respiratory exchange ratio, and energy expenditure measured every 5 minutes, and body weight and composition measured at the start and end of the period.

TAKEAWAY:

• Light-cycle access to HFD resulted in greater weight and fat mass gain than dark-cycle access. Mice with dark-cycle access to HFD had a greater increase in daily food intake than those with light-cycle access, but total daily energy intake was similar 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 activity slightly increased in mice with light-cycle access to HFD and slightly decreased in those with dark-cycle access, whereas dark-cycle activity remained unchanged in both groups.
• The daily respiratory exchange ratio decreased in the light-cycle group but remained unchanged in the dark-cycle group. Energy expenditure increased in the light-cycle group but not in the dark-cycle group.

IN PRACTICE:

“Our findings suggest that time-restricted access to high-fat diets promotes vastly different effects on feeding behavior, mainly food preferences and meal patterns, that parallel behaviors observed in humans dysregulated sleep-wake cycles (eg, night shift workers), a population that is at increased risk of developing obesity,” the authors of the study wrote.

SOURCE:

The study, led by Payam A. Fathi, Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine in Nashville, Tennessee, was published online in Obesity.

LIMITATIONS:

No limitations were discussed in the study.

DISCLOSURES:

This study was supported by grants from the National Institutes of Health with a shared instrument grant for the Vanderbilt Mouse Metabolic Phenotyping Center-Live. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.