Investigating the association between parental educational status and offspring obesity risk using the Japan Environment and Children's Study.

Background: Previous studies have demonstrated an inverse relationship between socioeconomic status and childhood obesity in affluent nations, with parental education as a key factor. However, the meaning of socioeconomic indicators may vary by race and country, and research on this topic in Asian countries is limited.

Objectives: We investigated the association between parents' educational status and childhood obesity in Japan.

Methods: We utilized data from Japan's birth cohort, recruiting participants from 2011 to 2014, and included 49 564 children. Parental educational status was categorized into four groups: both parents with lower education (LM-LF), mothers with higher education and fathers with lower education (HM-LF), mothers with lower education and fathers with higher education (LM-HF), and both parents with higher education (HM-HF). Multivariable logistic regression analyzed the association between parental education and overweight/obesity among 4-year-old children.

Results: Of the participants, 17.9%, 16.9%, 16.2% and 15.4% were overweight/obese; and 5.5%, 4.6%, 4.4% and 3.8% were obese in LM-LF, HM-LF, LM-HF and HM-HF groups, respectively. When the reference group was defined as children born to parents with HM-HF, the adjusted odds ratios for overweight/obesity in LM-LF, HM-LF and LM-HF were 1.13 (95% confidence intervals [CI]: 1.06-1.21), 1.08 (95% CI: 1.01-1.15) and 1.03 (95% CI: 0.95-1.12); and those for obesity were 1.34 (95% CI: 1.20-1.50), 1.16 (95% CI: 1.04-1.31) and 1.11 (95% CI: 0.96-1.28), respectively.

Conclusions: Lower educational status in both parents was associated with overweight/obesity among 4-year-old children in Japan. Public policies might target parents with lower education to prevent childhood obesity.