Parenting styles in relation to childhood obesity, smoking and drinking: A gene–environment interaction study

Background: The present study assessed gene–environment interactions linking maternal parenting styles to childhood obesity and alcohol and tobacco use. Methods: Data were retrieved from the first wave of the German Twin Family Panel. Participants comprised three birth cohorts, aged 5, 11 and 17 years, with approximately 500 pairs of same-sex monozygotic twins and 500 pairs of same-sex dizygotic twins per cohort. Self-reported parenting styles were measured in five dimensions: emotional warmth, psychological control, negative communication, monitoring and inconsistent parenting. Outcome variables included children's body mass index z-score (BMIz) and smoking and alcohol drinking frequency. Gene–environment interaction models were used to assess how parenting styles might moderate genetic and environmental influences on BMIz and smoking and drinking behaviours. Results: A positive interaction of genetic effects with psychological control was found for BMIz at age 5 years, indicating that genetic influences on BMIz increased with psychological control. No interaction effect was found for BMIz at ages 11 and 17 years. Regarding adolescent smoking, positive interaction between genetic effects and negative communication was found, indicating that genetic influences on smoking increased with negative communication. There was no significant moderating effect of parenting styles on adolescent drinking. Conclusions: The present study found preliminary evidence indicating that parenting styles moderated genetic and environmental impacts on body weight status and smoking. Moderation effects of parenting on BMIz were observed only at a very young age. The moderating effects of parenting influenced adolescent smoking but not drinking.