Bidirectional relationships between appetitive behaviours and body mass index in childhood: a cross-lagged analysis in the Generation XXI birth cohort.

Abstract

Appetitive behaviours have been associated with body mass index (BMI). However, existing data were largely derived from cross-sectional studies and cannot provide insight into the direction of associations. We aimed to explore the bidirectionality of these associations in school-age children. Participants are from the Generation XXI birth cohort, assessed at both 7 and 10years of age (n = 4264; twins excluded). The Children's Eating Behaviour Questionnaire (CEBQ) was used to measure appetitive behaviours (8 subscales). Anthropometrics were measured and WHO BMI z-score was calculated. Cross-lagged analyses were performed to compare the magnitude and direction of the associations (behaviours at 7years to BMI z-score at 10years and the reverse) (covariates: child's sex, physical exercise, maternal age and education; plus BMI z-score at age 7 or, in the reverse direction, the subscale score). In cross-lagged analyses, appetitive behaviours at 10years of age (apart from emotionalundereating) were shown to be reactive to the child BMI z-score at 7years of age. Only slowness in eating was significantly related to subsequent BMI. However, the strongest association was from the child BMI z-score to the behaviour (βstandardized = -0.028 compared with βstandardized = -0.103, likelihood ratio test p < 0.001). BMI at age7 was related to appetitive behaviours at 10years of age, rather than the reverse. This suggests that children with a higher BMI in middle childhood are at increased risk of developing an avid appetite over time.