Adrenocortical regulation, eating in the absence of hunger and BMI in young children

The purpose of this study was to examine relations among adrenocortical regulation, eating in the absence of hunger, and body mass index (BMI) in children ages 5-9years (N=43). Saliva was collected before and after the Trier Social Stress Test for Children (TSST-C), and was later assayed for cortisol. Area under the curve with respect to increase (AUC_i) was used as a measure of changes in cortisol release from baseline to 60min post-TSST-C. Age- and sex-specific BMI scores were calculated from measured height and weight, and eating in the absence of hunger was assessed using weighed food intake during a behavioral procedure. We also included a measure of parents' report of child impulsivity, as well as family demographic information. Participants were stratified by age into younger (5-7years) and older (8-9years) groups. In younger children, parents' reports of child impulsivity were significantly and positively associated with BMI; cortisol AUCi was not associated with BMI or eating in the absence of hunger. In older children, however, greater stress-related cortisol AUC_i was related to higher BMI scores and greater energy intake in the absence of hunger. The results suggest that cortisol AUC_i in response to psychosocial stress may be linked to problems with energy balance in children, with some variation by age.