Sustained effect of habitual feeding time on daily rhythm of core body temperature in mice

Hitoshi Ando; Naoto Nagata; Takashi Hosono; Nazmul Hasan; Jun-Ichi Morishige; Takiko Daikoku; Yoshiko Maida; Masanori Ono; Tomoko Fujiwara; Hiroshi Fujiwara

doi:10.3389/fnut.2022.966788

Sustained effect of habitual feeding time on daily rhythm of core body temperature in mice

Front Nutr. 2022 Aug 22:9:966788. doi: 10.3389/fnut.2022.966788. eCollection 2022.

Authors

Affiliations

¹ Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
² Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
³ Division of Animal Disease Model, Research Center for Experimental Modeling of Human Disease, Kanazawa University, Kanazawa, Japan.
⁴ Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan.
⁵ Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo, Japan.
⁶ Department of Human Life Environments, Kyoto Notre Dame University, Kyoto, Japan.

Abstract

Background and aim: Circadian clocks in most peripheral tissues are entrained mainly by feeding. Therefore, this study aimed to investigate whether the daily rhythm of core body temperature (CBT), including the effect of diet-induced thermogenesis, varies according to habitual feeding time.

Methods: Wild-type and uncoupling protein 1 (UCP1) knockout mice were fed only during the first 4 h (Breakfast group) or the last 4 h of the dark period (Dinner group) for 17 days. On day 18, both groups were fed twice for 2 h, at the same starting times. Locomotor activity and CBT were measured continuously during the experiment.

Results: On day 18, CBT increased at the beginning of each feeding period, regardless of the group and strain. However, the CBT increase induced by the first meal decreased sharply in the Breakfast group and mildly in the Dinner group; the opposite was observed after the second meal. In UCP1 knockout, but not wild-type, mice, the total amount of CBT was significantly lower in the Dinner group than in the Breakfast group. These effects were mostly independent of the locomotor activity and food intake.

Conclusion: These results reveal that the effect of habitual feeding time on the daily rhythm of CBT is sustained at least until the following day. These effects may be mediated by both UCP1-dependent and -independent mechanisms.

Keywords: circadian rhythm; core body temperature (CBT); diet-induced thermogenesis (DIT); meal timing; skipping breakfast.