Mediation by parent health literacy and behaviour of socioeconomic inequality in child overweight

BACKGROUND: Socioeconomic inequalities contribute to childhood overweight. Identifying mediators could help reduce these inequalities.

OBJECTIVE: We assessed to what extent and how parental health literacy and health behaviours mediate the relationship between parental socioeconomic status and childhood overweight.

METHODS: Data were taken from the multigenerational prospective Dutch Lifelines Cohort Study. We included 6683 children, baseline age 9.8 years (SD = 2.6), with an average follow-up of 36.2 months (SD = 9.3). Overweight was defined using age- and sex-specific cut-offs. Three indicators of socioeconomic status were included: education, income and occupation. We assessed the mediating role of parental health literacy and health behaviours (smoking, diet, physical activity and alcohol) using causal mediation.

RESULTS: Four additional years of education and an SD-increase in both income and occupation decreased the odds of childhood overweight by 42%, 12% and 20%, respectively. Only parental smoking independently mediated the relationship of both education (6.6%) and occupation (5.7%) with overweight. Parental health behaviours jointly explained 8.4% (education), 19.4% (income) and 9.8% (occupation) per relationship. Lastly, adding parental health literacy explained 10.8% (education), 27.4% (income) and 13.3% (occupation) of these relationships.

CONCLUSIONS: We found large socioeconomic inequalities in childhood overweight. Remarkably, parental smoking was a key mediator. Therefore, prevention targeting smoking may reduce socioeconomic inequalities in childhood overweight.