Box 1: Description of population, intervention, comparator, outcomes and setting

Population
• Children and youth aged 0–18 years
• Normal-weight or mixed-weight populations

Interventions
• Behavioural (diet, exercise, diet plus exercise or lifestyle) interventions for prevention of weight gain

Comparator
• Intervention effectiveness: no intervention, usual care or minimal intervention (e.g., newsletter or single information session on healthy living)
• Intervention harms: any type of comparison group or no comparison group

Outcomes
• Intervention effectiveness: change in body mass index (BMI) and BMI z-score, change in prevalence of overweight or obesity
• Intervention harms: disordered eating, psychological distress (e.g., anxiety), deficits in micronutrients, abnormal growth trajectory and growth restriction

Settings
• Generalizable to Canadian primary care or feasible for use in or referral from primary care; interventions should be initiated through (or feasible within) a primary care setting and (could be) delivered by a health care professional (e.g., physician, psychologist, nurse or dietician).