Cross-sectional and longitudinal associations between sedentary behavior and behavioral problems in children with overweight/obesity

Background: Sedentary behaviors (ST) are linked to children's mental health, including internalizing and externalizing problems. Research on these associations in children with overweight/obesity is limited. To this end, we examined cross-sectional and longitudinal associations between sedentary time (ST) and behavioral problems in children with overweight/obesity, followed by an investigation of potential sex-related differences. Methods: We included 2273 children with overweight/obesity (49.9 % boys) from the UK Millennium Cohort Study. Accelerometer-measured sedentary time (ST) and MVPA were collected at age 7, and behavioral problems were assessed at ages 7 and 11 via the Strengths and Difficulties Questionnaire (SDQ). General linear models were used to examine how ST at 7 years of age was cross-sectionally and longitudinally associated with externalizing and internalizing, while ethnicity, SDQ scores, parental psychological distress, highest parental education, household poverty, and moderate-to-vigorous physical activity (MVPA) were statistically controlled. These analyses are followed by an analysis investigating sex-related differences. Results: In the cross-sectional analyses, more ST was associated with fewer externalizing problems at 7 years among boys (β: −0.008, 95 % CI: −0.013, −0.003) and girls (β: −0.006, 95 % CI: −0.011, −0.001) without controlling for MVPA. More ST at 7 years was associated with fewer externalizing problems (β: −0.010, 95 %CI: −0.015, −0.004) only among boys when adjusting for MVPA. In the longitudinal analysis, more ST at 7 years was associated with fewer externalizing problems at 11 years for boys (β: −0.006, 95 %CI: −0.010, −0.001) and girls (β: −0.007, 95 %CI: −0.012, −0.002) without controlling for MVPA. When adjusting for MVPA at 7 years, more ST at 7 years was associated with fewer externalizing problems at 11 years for girls (β: −0.006, 95 %CI: −0.013, 0.000). Conclusions: In overweight/obese children, device-measured ST at the age of 7 years predicted fewer caregiver-reported externalizing problems at the age of 11 years, with boys showing stronger cross-sectional and girls longitudinal associations after MVPA adjustment. This suggests that the behavioral relationship of ST differs by sex and developmental stage, potentially warranting context-specific interventions to counteract its negative mental health influence.