Examining Direct and Indirect Mechanisms of Parental Influences on Youth Physical Activity and Body Mass Index

This study used social cognitive theory to compare the direct versus indirect effects of parent physical activity, sedentary behavior, and body mass index (BMI) on youth physical activity and BMI. Instrumental support, co-participation, and encouragement were examined as potential mediators of the relation between parent and child health factors. Participants ( n = 123) were ethnically diverse youth aged 8–14 years of age (mean age of 11.9; SD = 1.9; 40% female) and their parents. Youth and parents completed study questionnaires and had their height and weight measured. Youth also wore accelerometers to determine daily steps. Path analyses were conducted to assess mediational pathways between study variables. Parent physical activity and parent BMI influenced youth physical activity and BMI directly and indirectly through instrumental support and encouragement. Higher levels of instrumental support were associated with more physical activity, particularly for boys suggesting different patterns for socialization processes. Higher levels of encouragement were associated with higher BMI. The current study provides support for social cognitive theories and identified the specific effects of parent characteristics on physical activity as compared to BMI and suggest that encouragement may not be an effective strategy to reduce BMI. Highlights Parents have direct and indirect influences on youth physical activity and BMI. Parental instrumental support mediates the relation between parent and youth physical activity; higher levels of support are associated with higher levels of physical activity. Parental encouragement mediates the relation between parent and child BMI; higher levels of encouragement are associated with higher levels of BMI. Sex differences emerged such that instrumental support is associated with daily steps for boys, but not for girls.