Experimental scheme. C57BL/6J mice were fed a Western diet (WD) for 5 weeks under ad libitum access to food and water or under an IF (5:2) regimen. Mice undergoing an IF (5:2) regimen were divided into either fasting initiation in the inactive phase (7 a.m.–7 a.m.—a.m.) or fasting initiation in the active phase (7 p.m.–7 p.m.—p.m.). At the end of the 5 weeks, mice fed under ad libitum conditions were sacrificed in a fed state, while mice undergoing the IF (5:2) regimen were sacrificed after a 24—h fast (fasted state). Mice undergoing an IF (5:2) regimen initiated in the inactive phase were sacrificed at 7 a.m. (ZT = 0—light on), while mice undergoing an IF (5:2) regimen initiated in the active phase were sacrificed at 7 p.m. (ZT = 12—light off). Two distinct groups of ad libitum mice were sacrificed under a fed state either at 7 a.m. (ZT = 0—light on) or at 7 p.m. (ZT = 12—light off).
