Estimating Reductions in Ethnic Inequalities in Child Adiposity from Hypothetical Diet, Screen Time, and Sports Participation Interventions.

Abstract

Childhood obesity is a global epidemic, and its prevalence differs by ethnicity. The objective of this study was to estimate the change in ethnic inequalities in child adiposity at age 10 resulting from interventions on diet at age 8 and screen time and sports participation at age 9. We conducted a population-based cohort study, the Generation R Study, from 9,749 births in Rotterdam (2002-2006), of which 9,506 children remained in the analysis. We measured ethnicity, diet, screen time, and sports participation through questionnaires; we measured weight, body mass index (BMI), fat mass index, and fat-free mass index directly. We used sequential G-estimation to estimate the reduction in inequality that would result from the interventions. We observed that sociodemographic characteristics, diet, screen time, sports participation, and all adiposity measurements were more favorable in children from Western versus non-Western ethnic backgrounds: weight = -1.2 kg (95% confidence interval [CI] = -1.7, -0.8), BMI = -1.0 kg/m (CI = -1.2, -0.9), and fat mass index = -0.8 kg/m (CI = -0.9, -0.7). We estimated that extreme intervention (maximum diet score of 10, no screen time, and >4 hours/week of sports) reduced ethnic inequalities by 21% (CI = 8%, 35%) for weight, 9% (CI = 4%, 14%) for BMI, and 9% (CI = 6%, 13%) for fat mass index. A diet score ≥5 points, screen time ≤2 hours/day, and sports participation >2 hours/week reduced ethnic inequalities by 17% (CI = 6%, 28%) for weight, 7% (CI = 3%, 11%) for BMI, and 7% (CI = 4%, 10%) for fat mass index. Our results are consistent with the hypothesis that interventions integrating diet, screen time, and sports participation have a moderate impact on reducing ethnic inequalities in child adiposity.