Diurnal variation of liver glycogen and plasma free fatty acids in rats fed ad libitum or single daily meal

TLDR: The magnitude of both rhythms was accentuated by meal-feeding so that the average levels of both glycogen and free fatty acids over the twenty-four hour period were slightly higher than in rats fed ad libitum.

Abstract: In rats allowed to eat ad libitum, liver glycogen and plasma free fatty acids varied rhythmically during a twenty-four hour period. There was an inverse relationship between their levels, i.e., at 8 p.m., glycogen was lowest and free fatty acids were highest, whereas at 5–8 a.m., the converse was true. Feeding a single daily meal (from 8 a.m. to noon) caused a shift in phase of about twelve hours in both rhythms, with the inverse relationship between glycogen and free fatty acid levels again apparent. The magnitude of both rhythms was accentuated by meal-feeding so that the average levels of both glycogen and free fatty acids over the twenty-four hour period were slightly higher than in rats fed ad libitum.