Body mass index and parent-reported self-esteem in elementary school children: evidence for a causal relationship.
OBJECTIVE
To clarify relationships between body mass index (BMI) and self-esteem in young children at a population level. To assess whether low self-esteem precedes or follows development of overweight/obesity in children.


METHODS
Prospective cohort study in elementary schools throughout Victoria, Australia. Child BMI and self-esteem were measured in 1997 and 2000.


METHODS
Random sample of 1,157 children who were in the first 4 y of elementary school (aged 5-10 y) at baseline.


METHODS
BMI was calculated from measured height and weight, then transformed to z-scores. Children were classified as nonoverweight, overweight or obese based on international cut-points. Low child self-esteem was defined as a score below the 15th percentile on the self-esteem subscale of the parent-reported Child Health Questionnaire.


RESULTS
Overweight/obese children had lower median self-esteem scores than nonoverweight children at both timepoints, especially at follow-up. After accounting for baseline self-esteem, higher baseline BMI z-score predicted poorer self-esteem at follow-up (P=0.008). After accounting for baseline BMI z-score, poorer baseline self-esteem did not predict higher BMI z-score at follow-up. While nonoverweight children with low baseline self-esteem were more likely to develop overweight/obesity (OR=2.1, 95% CI=1.2, 3.6), this accounted for only a small proportion of the incidence of overweight.


CONCLUSIONS
Our data show an increasingly strong association between lower self-esteem and higher body mass across the elementary school years. Overweight/obesity precedes low self-esteem in many children, suggesting a causal relationship. This indicates that prevention and management strategies for childhood overweight/obesity need to begin early to minimise the impact on self-esteem.
Centre for Community Child Health, University of Melbourne & Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia. kylie.hesketh@mcri.edu.au
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K
Hesketh
M
M
Wake
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E
Waters
D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000209:etiology / Q000523:psychology*; D011446:Prospective Studies; D012307:Risk Factors; D012649:Self Concept