Food, activity and family -: environmental vs biochemical predictors of weight gain in children

Objective: To identify whether measures of energy intake and expenditure predict excessive weight gain over time in children and to describe how these measures relate to similar measures in parents. Design: Prospective, descriptive study over 12 months with no intervention. Setting: University teaching hospital. Subjects: Children aged between 6.0 and 9.0 y. Recruitment was through advertisement. A total of 59 children (30 F), 41 mothers and 29 fathers. In all, 41 (69%) of the children were reviewed at 12 months (20 F). Results: No significant correlations were identified between body mass index (BMI) z-score change in children over 12 months for any dietary variable or for any measures of energy expenditure, including hours of television viewing or percent time spent in low-, moderate- or high-intensity activity. The BMI z-score change over 12 months was significantly correlated with LDL cholesterol and Apo B/ApoA-1 ratio, independent of percent body fat (r = 0.45, P = 0.01; r = 0.37, P = 0.03). A significant positive correlation was found for mothers and girls for percent time in moderate to high activity (r = 0.44, P = 0.03) and between fathers and children for percent time spent in low activity (r = 0.43, P = 0.005). Conclusions: The study has been unable to identify environmental predictors that indicate propensity to faster weight gain over time in this cohort of children, but has extended the evidence on lifestyle-influenced biochemical predictors that do. An overall lack of vigorous activity in this age group, and correlations between parental and child activity and inactivity have been identified.