Objectives
Parental underdetection of child underweight and overweight/obesity may negatively affect children's longer‐term health. We examined psychological/behavioural mechanisms of a very low‐intensity intervention to improve acknowledgement and understanding of child weight after feedback from a school‐based weight monitoring programme.
Design
This sub‐study was nested within a larger 3‐arm cluster‐RCT (1:1:1; N = 57,300). Parents in all groups received written postal feedback on their child's weight classification. Intervention participants received an enhanced feedback letter with computer‐generated photorealistic images depicting children of different weight classifications, and access to a website about supporting healthy weight, once (intervention one) or twice (intervention two; repeated 6 months after first ‘dose’).
Methods
A quantitative process and outcome evaluation using baseline and 12‐month BMI z‐scores of an opt‐in sub‐sample of 502 children aged 4–5 and 10–11. Children completed dietary reports, used accelerometers (MVPA), and self‐reported self‐esteem; 10–11‐year‐olds also self‐reported quality of life and dietary restraint. Parents reported perceptions of child's weight classification, and their intentions, self‐efficacy, action planning and coping planning for child physical activity, dietary intake; parents of 4–5‐year‐olds reported their child's quality of life.
Results
Neither intervention differentially improved parental acknowledgement or understanding of weight classification at follow‐up, although parents in all groups reported better acknowledgement after receiving feedback. The interventions did not affect behavioural/psychological determinants, weight outcomes, children's self‐esteem, dietary restraint or quality of life.
Conclusions
The interventions neither improved parental acknowledgement of child weight, child BMI z‐scores and their psychological/behavioural determinants, nor worsened psycho‐social sequelae.
ORCID: 
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)