Long-Term Effects of a Primary Weight Gain Prevention Intervention among Healthy Weight Obesity Susceptible Children: Results from the Healthy Start Study

Introduction: Primary prevention is a public health strategy that hitherto has not been widely applied in obesity prevention research. The objectives were to examine the long-term effects of the Healthy Start primary obesity prevention study, an intervention conducted among healthy weight children susceptible to develop obesity. Methods: At baseline, children (2–6 years) were allocated to the intervention group (n = 271), the control group (n = 272), or the shadow control group (n = 383). Children in the shadow control group had no contact with project staff during the intervention period (1.3 years on average). The intervention was designed to deliver individually tailored improvements in diet and physical activity habits, optimization of sleep quantity and quality and reduce family stress. After the intervention was completed, height and weight at school entry were obtained from the Danish National Child Health Register when children were around 7 years. The average follow-up time was 2.7 years after baseline. Linear regression analyses on annual changes in BMI (ΔBMI) and BMI z-scores (ΔBMIz) were conducted. Results: At mean 2.7 years after the baseline examination, no differences were observed between the intervention and control group in ΔBMI (β = 0.07 [−0.02; 0.15], p = 0.14) or ΔBMIz (β = 0.04 [−0.02; 0.10], p = 0.19). Likewise, no differences were observed between the intervention and shadow control group in ΔBMI (β = −0.03 [−0.12; 0.06], p = 0.50) or in ΔBMIz (β = −0.02 [−0.08; 0.05], p = 0.62). Conclusion: We are still in urgent need of more primary overweight prevention interventions to begin to understand how to prevent that healthy weight children develop overweight.