Feeding and Eating Disorders in the Context of Circadian Rhythms

A circadian rhythm is a 24-hour rhythm controlled by a master clock, the suprachiasmatic nucleus, and driven by synchronizing internal/external zeitgebers. Food intake is one of the most important external cues/zeitgebers. Studies in humans and animals have shown that misalignment of food intake leads to chronodisruption, which is associated with metabolic disruption, obesity, and disordered eating attitudes. The term chronotype, which expresses the circadian typology, has been classified into 3 main types that represent the differences in the reflection of circadian rhythms shown in human studies on daily behaviors. It has been reported that evening-type individuals are more prone to disrupted eating attitudes, such as skipping meals, eating at night, and consuming a calorie-rich diet. In addition, eating disorders up to the diagnostic level is associated with the evening type. The bidirectional relationship between impaired circadian rhythms and disordered eating attitudes has brought chronotherapeutic interventions, which are biological rhythm-oriented treatment approaches, to the agenda. Bright light therapy has been found to reduce bulimic eating behaviors and night eating symptoms. More evidence is needed regarding the effect of chronotherapeutic approaches on metabolic disorders, disordered eating attitudes, and eating disorders associated with obesity.