Cross-sectional associations between body mass index and social-emotional wellbeing among differentially active children

Background: This study assessed gender-specific associations between BMI and social-emotional wellbeing (SEW) among differentially active 7-year-old children. Methods: Data is from wave four of the UK Millennium Cohort Study, collected in 2007-08. Children wore an ActiGraph accelerometer for 7 consecutive days and measures of stature and body mass were taken. BMI was calculated from stature and body mass (kg/m²). Parents/carers completed the Strengths and Difficulties Questionnaire (SDQ). Six-thousand-eleven children (3073 girls) had complete data. Mean minutes per day spent in moderate to vigorous physical activity (MVPA) were calculated for each child. Gender-specific MVPA quartile cut-off values categorised boys and girls separately into four graded groups representing the least (Q1) through to the most active (Q4) children. Adjusted linear regression analyses examined associations between BMI and SDQ scores. Gender-specific analyses were conducted separately for MVPA quartiles. Results: BMI was positively associated with peer problems for Q1 and Q2 boys and girls, conduct problems for Q2 and Q4 boys, emotional problems and prosocial behaviour for Q2 boys, and total difficulty scores for Q1 girls and Q2 boys (p<0.05). Conclusions: Our results revealed that BMI was positively associated with SEW difficulties among the low active children but not the high active children. Further research examining the concurrent effect of diet and MVPA on child weight status and SEW is needed.