Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, if he will make an assessment of the effectiveness of using Body Mass Index as a way of measuring childhood obesity through the National Child Measurement Programme.

In January 2025, the National Institute for Health and Care Excellence (NICE) reviewed evidence and assessed the most accurate methods for identifying childhood obesity and thresholds for predicting the risk associated with overweight and obesity. They recommend that Body Mass Index (BMI) centile (BMI adjusted for age and sex) is a useful practical measure for estimating and defining overweight and obesity in children and young people.

The Government accepts NICE’s evidence review, assessment and recommendations as national guidance for measuring childhood obesity through the National Child Measurement Programme, including that:

• BMI centile needs to be interpreted with caution because it is not a direct measure of central adiposity (the accumulation of excess fat in the abdominal area, which directly relates to health risks such as type 2 diabetes, hypertension and cardiovascular disease).
• Waist circumference and a waist to height ratio measurement is considered alongside a child’s BMI centile in individual clinical assessments to predict health risks associated with central adiposity. Based on this recommendation, additional information about measuring a child’s waist to height ratio using the NHS waist to height calculator has been included on NHS.UK to support parents in understanding their child’s long-term health risks.
• A child’s BMI centile should always be plotted on the Royal College of Paediatrics and Child Health UK-World Health Organization (WHO) growth charts and BMI charts.