Table 1

Framework and data collection for the process evaluation

Component	Definition	Data collection
Recruitment	Success of methods used to approach and recruit participants	Parent self-reported questionnaire at baseline: how they heard about the trial
Reach	Degree to which an intended audience participates in an intervention	Parent self-reported questionnaire at baseline: sociodemographic characteristics, to define if participants reflect the population Child height and weight measurements
Dose received	Extent of engagement with the FFH and UC interventions by the target population	Parent evaluation questionnaires of each session and end of programme (FFH only) Parent and child one-to-one structured interviews at 3 months (ie, post-intervention)
Dose delivered	The ‘amount’ of intervention provided by the FFH intervention team	Attendance data Facilitators' weekly evaluation forms Facilitators focus groups
Fidelity	The extent to which the FFH intervention was delivered as planned ie, quality and integrity of intervention	Fidelity visits for three to four sessions Facilitators’ focus groups
Perceived impact of intervention	Assessment by intervention participants of the impact of the intervention on themselves	Parent one-to-one structured interviews at 12 months (from baseline)