Tracking Preschoolers' Lifestyle Behaviors and Testing Maternal Sociodemographics and BMI in Predicting Child Obesity...

Longitudinal data investigating tracking of children's lifestyle behaviors and predictors of childhood obesity are limited.

We examined changes in children's lifestyle behaviors (dietary, physical activity, and screen time) from ages 2-5 y to determine if maternal sociodemographic factors and BMI predict child obesity at 3.5 y and 5 y.

Data were obtained from 667 first-time mothers who were recruited into the Healthy Beginnings Trial at 24-34 weeks of gestation in Sydney, Australia. Child lifestyle behaviors were assessed using face-to-face questionnaire interviews with mothers. To measure child and maternal anthropometry, BMI (in kg/m2) was calculated using measured height and weight. Children were categorized as overweight or obese based on the International Obesity Task Force criteria. We used 1-factor repeated-measures ANOVA to track preschoolers' lifestyle behaviors and multiple logistic regression to determine obesity predictors.

In children aged 2-5 y, consumption of vegetables (ηp2 = 0.06; P < 0.005) and milk (ηp2 = 0.02; P < 0.001) decreased, whereas physical activity (ηp2 = 0.07; P < 0.001) increased. Discretionary foods (sweet snacks, fast foods, salty snacks, processed meats, confectionary) (ηp2 = 0.03-0.25; P ≤ 0.01) and screen time (ηp2 = 0.39; P < 0.001) increased. Maternal BMI (in kg/m2) (Exp β: 1.06; 95% CI:1.01, 1.12 ; P=0.02), marital status (married/de facto compared with single) (Exp β: 0.06; 95% CI:0.01, 0.26; P < 0.001), and child BMI at 2 y (Exp β: 1.82; 95% CI: 1.46, 2.27; P < 0.001) predicted overweight/obesity at 3.5 y. Child BMI at 3.5 y (Exp β: 3.51; 95% CI: 2.50, 4.93; P < 0.001) predicted obesity at 5 y.

Poor dietary and lifestyle behaviours track in early childhood, with maternal single-parent status and high maternal and child BMI at 2 y predicting earlier obesity onset.