Relation between salivary cortisol as stress biomarker and dietary pattern in children

Purpose: Psychological stress has been suggested to result in hormonal effects (e.g. changes in cortisol pattern) that may change food selection in unhealthy ways. This study examines whether children's dietary pattern is indeed related to salivary cortisol levels. Methods: In 323 children (5-10 years old) participating in the Belgian ChiBS study, salivary cortisol samples, a biomarker for stress, was sampled when waking up, 30 and 60 min after wake up and in the evening on two consecutive weekdays. Data on the children's dietary pattern (frequency of sweet foods, fatty foods, snacks, fruit and vegetables) was collected with a food frequency questionnaire. Multilevel time modelling was used with adjustments for sex, age, body mass index, parental education and wake up time. Results: Higher overall cortisol levels and a large cortisol awakening response (CAR) were associated with more frequent consumption of sweet foods. A steeper diurnal cortisol decline was associated with a higher sweet, fatty and snack food consumption frequency. No associations with fruit and vegetables consumption were found. Conclusions: High cortisol levels were linked to an unhealthier dietary pattern (more fatty food, snacks and especially sweet food). This supports the theory of cortisol-induced comfort food preference and strengthens the stress-diet relation. (C) 2013 Elsevier Ltd. All rights reserved.