People living with obesity are 70% more likely to be hospitalised or die from an infectious disease, according to a major study published in The Lancet. Researchers estimate that one in 10 infection-related deaths globally – around 600,000 annually – are linked to the condition.
The study, which analysed data from over 500,000 adults in Finland and the UK, found the elevated risk applied to a wide range of infections including flu, pneumonia, gastroenteritis, urinary tract infections and Covid-19. The risk increased with higher body mass index (BMI).
Dr Solja Nyberg, first author from the University of Helsinki, warned that the problem could worsen as obesity rates rise. She called for policies to support weight loss, such as affordable healthy food and opportunities for physical activity, and urged those with obesity to keep up to date with vaccinations.
Lead author Professor Mika Kivimäki of University College London said the link suggests obesity weakens the immune system. He noted that trials of GLP-1 weight-loss drugs have shown that reducing obesity lowers the risk of severe infections, though more research is needed to confirm the mechanisms.
The proportion of infection deaths attributable to obesity varied by country: about one in six in the UK, one in four in the US, and as low as 1.2% in Vietnam. The researchers cautioned that the findings are observational and do not prove causality.
