Study Findings: Obesity linked to higher risk of severe infections

Adult obesity significantly increases the risk of severe infections and infection-related deaths, according to a large international study published in The Lancet. The research suggests that around one in ten infection-related deaths globally may be linked to obesity, highlighting a growing but often overlooked public health concern.

The multicohort study analysed data from more than 540,000 adults from Finnish population studies and the UK Biobank, tracking hospitalisations and deaths related to infectious diseases over more than a decade. Researchers examined the relationship between body mass index (BMI) and the risk of severe infections caused by bacteria, viruses, parasites, and fungi.

Results showed a clear dose–response relationship, meaning the risk increased with higher levels of obesity. Individuals with severe obesity faced nearly three times the risk of hospitalisation or death due to infections compared with people of healthy weight.

The findings were consistent across a wide range of infections, including respiratory, gastrointestinal, and skin infections. Scientists say obesity may weaken immune defenses through chronic inflammation and metabolic disturbances.

With global obesity rates continuing to rise, experts warn that addressing obesity could also reduce the burden of infectious diseases worldwide.