Hunger, too, has a natural circadian rhythm. If hunger were simply due to lack of food, we would consistently be hungry in the morning after the long overnight fast. But personal experience and studies show that hunger is lowest in the morning, and breakfast is typically the smallest, not the largest, meal of the day. Hunger follows a natural, circadian rhythm that is independent of the eat/fast cycle. Ghrelin, the hunger hormone, rises and falls in a natural circadian rhythm, with a low at 8:00 a.m. and a high at 8:00 p.m.
