Longitudinal associations between diet quality, sedentary behaviours and physical activity and risk of overweight and obesity in preschool children: The ToyBox-study

Background: Lifestyle behaviours related to diet and physical activity are associated with increased risk of obesity and evidence suggests that associations might be stronger when a synergetic effect is examined. Objective: To examine the cross-sectional and longitudinal associations between diet, screen time (ST) and step recommendations and risk of overweight and obesity in European preschoolers participating in the ToyBox-study. Methods: In this cluster-randomized clinical trial, 718 children (51.4% boys) from six European countries participated. Parents filled out questionnaires with information on socio-demographic status, step recommendations and ST. Results: Longitudinal results indicate that participants having a low Diet Quality Index (DQI), not meeting ST and step recommendations at T0 and T1 had higher odds of having overweight/obesity at T1 (odds ratio [OR] = 1.116; 95% confidence interval [CI] = 1.104–2.562) than those children having a high DQI and meeting ST and step recommendations at T0 and T1. Similarly, participants having a high DQI, but not meeting ST and step recommendations at T0 and T1 had increased odds of having overweight/obesity (OR = 2.515; 95% CI = 1.171–3.021). Conclusions: The proportion of participants having a low DQI, not adhering to both step and ST recommendations was very high, and it was associated with a higher probability of having overweight and obesity.