The relationship between night eating symptoms and disordered eating attitudes via insomnia and chronotype differences.

Humans' sleep timing and the psychological construct "diurnal preference" determines their "chronotype" (i.e., morning or evening type). Diurnal preferences can affect sleep-awake rhythms and eating behaviors. Our aim in this study was to examine the relationship between night eating symptoms and disordered eating attitudes by evaluating insomnia and chronotype differences in university students. The participants, 383 university students, filled out a package of psychological tools, including the Morningness-Eveningness Questionnaire, the Insomnia Severity Index, the Night Eating Questionnaire, and the Eating Attitude Test. One way analysis of variance was used to investigate the relationship of chronotypes with scale scores, and mediation regression analysis was used to investigate the indirect effects of night eating symptoms on disordered eating attitudes. Insomnia and night eating scores of the participants varied statistically according to chronotypes, and both insomnia and night eating scores were associated with the evening type. Findings show that night eating symptoms have a direct effect on the chronotype differences and insomnia and an indirect effect on disordered eating attitudes, by increasing insomnia scores. In conclusion, night eating syndrome may represent the misalignment of food intake and may shift the circadian rhythm to delayed sleep phase, acting as a peripheral oscillator in human.