The dependency of cyclical feeding behavior on internal and external cues.

Abstract

The food intake of ten hooded rats was measured every 6 hr. in several 24-hr. periods (1) with the light on 12 hr. and off 12 hr., (2) with the light on 24 hr., (3) with free access to water in combination with the light conditions, and (4) with 24-hr. water deprivation in combination with light conditions. It was found that cyclical eating behavior exists, to some extent, independently of any normal physiological rhythm, and, to some extent, independently of environmental cues. Interference with both internal rhythms and environmental cues, however, creates arhythmicity.