LAUSR

Abstract There is a lack of consistency in the literature that shows a relationship between chronotype, habits of eating and obesity in Iranian adults. This cross-sectional study was conducted on 850 individuals aged ≥ 18 years, selected from health houses of Tehran, Iran. Chronotype was assessed by Horne and Ostberg morningness–eveningness questionnaire. Specific eating habits, including breakfast skipping, intakes of fruits and vegetables, fast food, processed meats, soft drinks, coffee and tea, were assessed by dietary recalls. Weight, height, BMI, waist circumference, waist to hip ratio, waist to height ratio, visceral adiposity index, body roundness index and body adiposity index were based on measured values. We used logistic regression to investigate the association between chronotypes and anthropometric measures as well as eating habits. Morning- and intermediate/evening-type chronotypes accounted for 51·4 and 48·6 % of the total individuals, respectively. Moreover, intermediate/evening-type chronotypes were shown to have a lower education of diploma (53 %), employed (49·9 %) and smokers (11·6 %) compared with morning types (both sexes). We found that intermediate/evening-type chronotypes might not be significantly related to higher anthropometric measures and following unhealthy eating habits after controlling for confounders in men and women (all P > 0·05). Overall, both anthropometric measures and specific eating habits were not related to chronotype among Iranian adults. Further studies are needed to clarify these relations and to consider sleep disturbances.