A Coherent Family Support Model (Co-Fam) for Prevention and Management of Childhood Obesity: Protocol for a Hybrid Type 2 Effectiveness-implementation Trial

In this hybrid type 2 effectiveness-implementation study, a two-armed randomized controlled trial will randomize families to either the intervention arm receiving the More and Less program or the control arm receiving standard care from primary health care or a pediatric clinic. A matched control group will be identified from a national obesity register for supplementary comparison. Eligible participants are families with children aged 6-12 years with overweight or obesity, enrolled in schools implementing the Healthy School Start program. Effectiveness outcomes to evaluate the intervention are BMI z-score, parental feeding practices, diet and physical activity, child eating behaviour and intervention fidelity which will be measured at baseline, three and 12 months. Implementation outcomes will be evaluated in a process evaluation assessing reach, fidelity, acceptability, feasibility and cost, assessed at 12 and 24 months using a mixed methods approach.