Does child-parent resemblance in body weight status vary by sociodemographic factors in the USA?

Background: Clustered obese parents and children are prevalent, but there is little knowledge about whether and how child-parent resemblance varies by sociodemographic groups. Methods: This paper used nationally representative data from the National Health and Nutrition Examination Survey III (NHANES: 1988-1994). We matched 4958 parents with 6765 children aged 2-16 years old for whom we had complete data on body mass index (BMI), overweight and obesity status. Correlation coefficients and κ statistics between parents' and children's BMI and body weight status were calculated for different sociodemographic groups. Multivariate linear and logistic regression models were fit to study the child-parent resemblance and socioeconomic and demographic differences in the resemblance. Results: The child-parent correlation coefficients for BMI were greater in Caucasians than in minorities and greater in groups with higher socioeconomic status. The mother-child resemblance in BMI was negatively associated with child age (p<0.001). The mother- daughter resemblance in overweight was significantly lower in non-Hispanic blacks (OR=0.53, 95% CI (0.36 to 0.78)) and Mexican Americans (OR=0.58, 95% CI (0.36 to 0.93)) than in Caucasians. The father-child resemblance in overweight was significantly lower in high school graduates compared with those with lessthan-high-school-graduate fathers (OR=0.53, 95% CI (0.37 to 0.77) for father-son dyads and OR=0.69, 95% CI (0.50 to 0.96) for father-daughter dyads). Similar results were found for parent-child resemblance in obesity. Conclusions: Child-parent resemblance in body weight status exists across sociodemographic groups in the USA, but it varies by demographics and socioeconomic status.