Margaret Newport, graduate student in the laboratory of Dr. Holly Bates at Trent University presented results from her research on the effects of daylength (i.e. photoperiod) on body fat and circadian rhythm in white-footed mice at the 2021 Experimental Biology conference.
Both photoperiod (length of daylight) as well as temperature naturally vary with changing seasons and can impact an organism’s physiology. To differentiate between the effects of temperature and photoperiod, the research team exposed white-footed mice to varying daylength at ambient temperatures. Mice exposed to a short photoperiod had less visceral fat whereas mice exposed to the longer photoperiod ate 3x more food during the daylight than mice exposed to shorter photoperiods who predominantly ate during the dark. Keeping in mind that these mice are nocturnal, the long photoperiod mimicked humans snacking at night. They also found changes in genes associated with circadian rhythm.
As disruptions in circadian rhythm are associated with increased risk of obesity and metabolic diseases in humans, this research has implications for the development of treatment strategies to combat the current obesity epidemic.