Daily sedentary time, defined as out-of-school recreational screen time, will be measured using a single item adapted from the Youth Health - Physical Activity & Sedentary Behavior Module questionnaire. The question asks students to indicate the total time range in minutes spent sitting or lying down looking at a smartphone, tablet, computer, or TV outside of school during the previous day. Provided time intervals are adjusted depending on the age of the participant to facilitate accurate recall. Total sedentary time is calculated by assuming the midpoint of the time interval.

Energy expenditure through physical activity is estimated as total kilocalories (kcal) burned during moderate-to-vigorous (MVPA) and non-MVPA physical activity time, based on total physical activity time indicated from survey responses. Energy expenditure in kcal/minute is the product of the MET (metabolic equivalent) x BMR (base metabolic rate), where MET is assumed to be 5.5 for MVPA activities and 3.0 for non-MVPA activities, and BMR is based on age- and sex-adjusted Schofield equations. Total daily energy expenditure is then estimated using a MET of 1.2 for non-physical activity time, which is estimated as 24 hours less physical activity time.

Global dietary recommendations (GDR) score will be measured with an edited version of the Diet Quality Questionnaire (DQQ), which asks children whether they ate foods from each of 29 food groups in any of four meals (breakfast, lunch, dinner, snack) in the previous day. A simplified 16-food group version is used for children in grades 3-4. The total GDR is calculated based on sub-scores for consumption counts of food categories (fruits and vegetables, sugar-sweetened beverages, added sugars, saturated fats, fibre, starchy staples, dairy food, animal-source food).

Energy intake is estimated as total kilocalories (kcal) consumed based on responses to each item in the Diet Quality Questionnaire. Each item is assigned an estimated unweighted average kcal intake for children across al food items mentioned within that item. Kcal values will be summed across all items and mealtimes indicated to produce a total estimated energy intake for the previous date.

Net calories is estimated in kcal/day for each participant as total estimated energy expended minus total estimated energy intake

Experience of food insecurity within the home context will be measured using a single question item asking how often in the last month the participant worried about running out of food to eat at home, with pre-specified frequency response options ranging from never to every day. These questions are only asked to participants in grades 5 to 8.

Participation within a school food program will be measured using a single question item asking how often in the last month the participant ate food that was provided by the school for free (such as a breakfast, lunch, or snack), with pre-specified frequency response options ranging from never to every day. These questions are only asked to participants in grades 5 to 8.

Physical literacy (defined as the competence, confidence, and motivation to participate in a variety of sports and physical activities) will be measured using two questionnaire items adapted from the PLAY self tool. The items ask participants to indicated their level of agreement on a 4-point Likert-style scale to two statements regarding feeling confident when doing physical activities, and feeling happier when being active. These questions are only asked to participants in grades 5 to 8.

Perceptions/experiences of physical activity within the school context will be examined through a single questionnaire item related to feeling welcome when doing physical activity at school. The item ask participants to indicated their level of agreement on a 4-point Likert-style scale. This question is only asked to participants in grades 5 to 8.

Sense of belonging within one's school will be assessed using items capturing various aspects of school connection. Each item uses a 5-point Likert-style response based on how strong the respondent is feeling or the frequency of doing / feeling things over the last week. Two items adapted from the KIDSCREEN-27 questionnaire will be asked of all participants: feeling happy at school and having fun. Two additional optional items related to feeling safe at school and feeling a part of one's school will be asked among participants in grades 5-8 only. A total sense of belonging score will be calculated by summing available item responses based on participant grade.

Positive body image and body appreciation will be measured using items from the Body Appreciation Scale-2 for Children, which generates a sum score based on 8 items related to positive feelings and attitudes toward one's body. These optional measures will only be asked among participants in grades 5-8.

Sense of belonging within one's community will be assessed using five items adapted from a community cohesion scale used in the Health Behavior of School-aged Children study. Items assess aspects of community trust, safety, support, communication, and facilities. Items are scored using a 5-point Likert scale for level of agreement and then summed to calculate a total community belonging score. These optional items will only be asked among participants in grades 5-8.

Total number of people reached by each intervention will collected by local delivery partners for each intervention and aggregated quarterly during the intervention delivery phase to determine the total across all interventions.

Total number of children (0-18 years) reached by each intervention will collected by local delivery partners for each intervention and aggregated quarterly during the intervention delivery phase to determine the total across all interventions.

Total number target population (6-13 years) reached by each intervention will collected by local delivery partners for each intervention and aggregated quarterly during the intervention delivery phase to determine the total across all interventions.

Estimated impact on BMI is modelled using the PRIMEtime simulation model. Net calorie change (based on estimated net calories from questionnaire items) is translated into predicted changes in average body weight, which are then expressed as BMI z-scores.

Estimated impact on cardiovascular disease (CVD) incidence is modelled using the PRIMEtime simulation model. Predicted BMI changes are linked to risk equations for cardiovascular disease incidence and mortality, altering the projected disease burden.

Estimated impact on Type 2 diabetes incidence is modelled using the PRIMEtime simulation model. Predicted BMI changes are input into established risk models for type 2 diabetes, altering projected onset and prevalence.

Estimated impact on quality-adjusted life years (QALYs) is modelled using the PRIMEtime simulation model. Reductions in projected disease incidence and mortality are converted into gains in health-adjusted survival.

Estimated impact on disability-adjusted life years (DALYs) is modelled using the PRIMEtime simulation model. The model estimates years of healthy life gained by reducing both premature death and years lived with disability.

Cost-effectiveness of interventions is modelled using the PRIMEtime simulation model. Health care costs associated with each disease are combined with QALY/DALY projections to calculate incremental cost-effectiveness ratios (ICERs) and overall net monetary benefit.