About this release

This annual release from Public Health Scotland (PHS) provides statistics on high, low and healthy body mass index (BMI) for Primary 1 school children (those aged around 5 years old), and includes data for school years 2001/02 to 2022/23. Statistics in this release are derived from height and weight measurements collected at health reviews in Primary 1.

Main points

  • In school year 2022/23, 76.8% of Primary 1 children measured had a healthy weight, 21.9% were at risk of overweight or obesity and 1.3% were at risk of underweight.
  • Marked socioeconomic inequalities in child healthy weight persist, particularly in the percentage of children at risk of obesity. In 2021/22 15.5% of children living in the most deprived areas were in this category, compared with 7.3% of those living in the least deprived areas.
Image caption Percentage of Primary 1 children at risk of obesity by deprivation, school years 2001/02 to 2022/23, Scotland
  • Having been lower in the past two years, the proportion of children in the healthy weight category in 2022/23 was comparable to pre-pandemic levels.
  • Boys in Primary 1 remain slightly less likely than girls to have a healthy weight.
  • In school year 2022/23 a total of 48,995 children had valid height and weight measurements recorded in Primary 1. This is approximately 89% of children aged 5 in Scotland.


A child’s BMI is calculated by dividing their weight (in kilograms) by their height (in metres) squared. Children are then allocated to a healthy or unhealthy weight category by comparing their BMI to the range of BMIs seen among a reference group of children of the same age and sex.

This summary provides information on the proportion of children found to be at risk of having an unhealthy weight based on the thresholds used for monitoring the health of the child population (‘epidemiological thresholds’).

The full report also provides information on the proportion of children found to have an unhealthy weight based on the narrower clinical thresholds used by health professionals caring for individual children. Monitoring healthy weight across the child population is a way of seeing how well the needs of children are being met. Maintaining a healthy weight through childhood is associated with many health benefits.

Further information

The next release of this publication will be December 2024.

General enquiries

If you have an enquiry relating to this publication, please contact Dr Lynda Fenton at phs.childhealthstats@phs.scot.

Media enquiries

If you have a media enquiry relating to this publication, please contact the Communications and Engagement team.

Requesting other formats and reporting issues

If you require publications or documents in other formats, please email phs.otherformats@phs.scot.

To report any issues with a publication, please email phs.generalpublications@phs.scot.

Older versions of this publication

Versions of this publication released before 16 March 2020 may be found on the Data and Intelligence, Health Protection Scotland or Improving Health websites.

Last updated: 21 March 2024
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