People with obesity are up to 70 per cent more likely to be hospitalised or die from infectious diseases such as flu, COVID-19 and pneumonia, according to a study published in The Lancet.

The researchers said obesity was linked to one in ten infection-related deaths globally in 2023, though they cautioned that estimates of obesity’s overall global impact should be interpreted carefully.

Scientists from the UK and Finland noted that people with obesity faced a higher risk of hospitalisation or death due to SARS-CoV-2 infection during the COVID-19 pandemic. However, they said evidence on whether this association extended to infectious diseases more broadly had been limited.

To address this, the team analysed data from the UK Biobank and Finnish cohorts, covering more than 540,000 people. Participants’ body mass index (BMI) was recorded at enrolment and they were followed for an average of 13–14 years.

“(The) study of over 540,000 people suggests people with obesity are 70 per cent more likely to be hospitalised or die from an infectious disease; people with the most severe obesity face three times the risk,” the researchers said.

Based on global extrapolations, the team estimated that obesity may have contributed to 0.6 million of the 5.4 million infectious disease-related deaths worldwide in 2023, or 10.8 per cent.

“Our findings suggests that people living with obesity are significantly more likely to become severely ill or to die from a wide range of infectious diseases. As obesity rates are expected to rise globally, so will the number of deaths and hospitalisations from infectious diseases linked to obesity,” said author Solja Nyberg of the University of Helsinki in Finland.

Nyberg also stressed the need for urgent policies to help people stay healthy and support weight loss, including access to affordable healthy food and opportunities for physical activity.