Time-Restricted Feeding Affects Energy Metabolism in Lactating Striped Hamsters (Cricetulus barabensis, Cricetidae, Rodentia).

Lactation is a critical period in which mothers generally increase food intake and metabolism to meet high energy demands. In the present study, we examined the effect of time-restricted feeding (TRF) on lactating striped hamsters. On the day of litter birth, lactating females were assigned into 3 experimental groups that experienced 24-h ad lib feeding (Con), 12-h daytime feeding (DF), or 12-h nighttime feeding (NF). A group of non-lactating females with 24-h feeding (NL) served as an additional control. Our data show that lactating females had increased food intake, oxygen consumption, and small intestine mass but a decreased level of circulating melatonin, compared to the NL females. However, TRF manipulation significantly reduced the mother's food intake, the pup's body mass, and survival rate. In addition, TRF had some phase-specific (i.e., DF vs. NF) effects on facilitating body mass loss, decreasing CART, AgRP, and POMC gene expression in the hypothalamus, and increasing abundance in Desulfobacterota and Actinobacteriota in the gut microbiota of lactating females. Together, our data illustrate adaptive changes of lactating hamsters under TRF conditions, and highlight the importance of food access and dietary rhythm regulation in maternal and offspring health, development, and reproductive success. These findings not only expand our understanding of lactation biology and ecological feeding strategies but also highlight the significance of regular dietary patterns for lactating individuals, with particular emphasis on shift workers and other populations with irregular daily schedules.