Underweight Children Cost Health Services as Much as Those with Obesity

A new study from the University of Oxford reveals that underweight children need comparable medical support as those who are severely obese, challenging assumptions about childhood health priorities. The research, funded by the National Institute for Health and Care Research, used NHS electronic health records from over 268,000 children aged 2-15 across England to provide the first national picture of healthcare costs linked to children's weight. The study found that children with severe obesity had the highest excess costs, while healthcare use was substantially higher after weight was measured for underweight children.

Key Takeaways:

• The NHS incurs an estimated £340 million in additional healthcare costs annually due to weight-related health problems in children, not just obesity.
• Children with severe obesity have the highest excess costs, with an estimated £472 per year in additional healthcare costs.
• Girls with severe obesity cost more than boys, with an estimated £253 vs £138 annually.
• Only White children showed higher healthcare costs across all unhealthy weight groups.
• Healthcare use was substantially higher after weight was measured for underweight children, and moderately higher for children with severe obesity.
• Dr. Olu Onyimadu, lead researcher, suggests that the focus should be on the entire weight spectrum, not just obesity, and that underweight children may need comparable support and generate similar costs per capita to the NHS.
• The research provides NHS decision-makers with clear evidence about where to target resources to make the case for weight-management services.

Statistics:

• 2.5 million children in England are affected by childhood weight issues, costing the NHS an estimated £340 million each year.
• The number of children aged 2-15 with obesity has increased from 22.4% in 2017 to 28.8% in 2019 (https://www.nhs.uk/news/live-well/childhood-obesity/query-16-dec-2019).
• An estimated 10 million adults in England are obese, with the number expected to rise to 11.6 million by 2025 (https://www.nao.org.uk/report/obesity).
• 4 to 5-year-olds with severe obesity have the highest excess costs at £472 per year.
• Girls with severe obesity cost more than boys, with an estimated £253 vs £138 annually.
• Healthcare costs rise sharply after a child's weight is formally recorded, suggesting that identifying weight issues triggers additional medical support.

Sources:

• National Institute for Health and Care Research (NIHR)
• University of Oxford
• JAMA Network Open (https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2840038)
• The Guardian (https://www.theguardian.com/society/2025/jul/02/obesity-overweight-cost-estimate-nhs-study)
• Digital Journal (https://www.digitaljournal.com/world/underweight-children-cost-health-services-the-same-as-children-with-obesity/article)
• EurekAlert (https://www.eurekalert.org/news-releases/1101671)