Parents' perceptions of their child's weight among children in their first year of primary school: a mixed-methods analysis of an Australian cross-sectional (complete enumeration) study.

Background/objectives: To describe trends in overweight/obesity in early childhood for all children and those whose parents are concerned about their weight. To describe parents' perceptions of their child's weight and differences by their child's anthropometric and sociodemographic factors.

Subjects/methods: Analysis of the Kindergarten Health Check, a survey of all children enrolled in their first year of primary education in the Australian Capital Territory. Analysis of detailed data for 2014-2017, including qualitative analysis of parents' comments on weight, and trends for 2001-2017.

Results: 71,963 children participated in the survey between 2001 and 2017 (20,427 between 2014 and 2017). The average age of children (2001-2017) was 5 years and 9.6 months at the time of their physical health check. 2377 children (3.5%) were classified as obese based on measured body mass index (BMI) between 2001 and 2017, and a further 7766 (11.6%) overweight. Similar proportions were seen for 2014-2017. Among children with overweight/obesity in 2014-2017, 86.4% of parents (2479/2868) described their children's weight as healthy and 13.3% (382/2868) as overweight/obese. Just 11.5% (339/2946) of parents whose children were later measured with overweight/obesity identified having a concern about their child's weight. Parental comments varied widely and were often incongruent with the known health risks associated with their child's measured BMI. Comments from parents whose children were measured as obese often were normalising e.g., "born big, always big. Definitely NOT overweight, just bigger all over", whilst parents of children in the healthy range expressed concerns about underweight.

Conclusion: Parents do not accurately perceive their child's weight and few document concerns, even among children measuring in the obese BMI category. This lack of concern makes early interventions challenging as parents are in the "pre-contemplative" stage of behaviour change and may see public health campaigns or clinicians' attempts to address their child's weight as irrelevant or unhelpful.