Obesity associated with a 70% increased risk of severe infectious disease

Obesity Linked to Increased Infection Risks

According to a recent study, individuals living with obesity face a heightened risk of hospitalization and mortality from various common infections. This research indicates that being significantly overweight could have more detrimental effects than previously understood.

The findings, published in The Lancet, reveal that very overweight individuals are 70 percent more likely to experience severe infections from illnesses such as flu, pneumonia, gastroenteritis, and urinary and respiratory tract infections. This contrasts with the growing concern about obesity, which has more than doubled in the last thirty years and continues to escalate, pointing to risks that extend beyond chronic conditions like diabetes and heart disease.

Lead author Professor Mika Kivimäki from UCL’s Faculty of Brain Sciences commented on the study, suggesting that the link to various infectious diseases may involve “broad biological mechanisms.” It’s possible that obesity hampers the immune system’s ability to fend off infectious agents, leading to more severe illness outcomes.

Yet, the correlation is not consistent across all diseases; for instance, severely overweight individuals did not show an increased risk of death or hospitalization from HIV or tuberculosis.

The research, which involved 540,000 subjects from the UK and Finland, hints that obesity could account for over 10 percent of global deaths due to infectious diseases in 2023.

This connection was initially observed during the Covid-19 pandemic, prompting further investigation into its relevance to other infections. The results indicated that as body weight increased, so did the chances of severe outcomes, with the most obese individuals facing three times the risk of those with a healthy body mass index.

However, researchers noted that since the study was based on observational data, it does not establish causation, and the participants from the UK and Finland may not reflect the broader population.

They stressed the importance of improved access to affordable healthy foods and physical activity options. Solja Nyberg from the University of Helsinki emphasized the need for very overweight individuals to remain diligent with vaccinations, warning that as obesity rates climb globally, so too would the related deaths and hospitalizations from infectious diseases.

The study also found notable differences between countries regarding obesity-related infectious disease deaths. For instance, in 2023, the United States reported the highest rate among high-income nations, with a quarter of deaths linked to obesity, while the UK saw one in six. Vietnam had the lowest percentage at just 1.2 percent.

Sara Ahmadi-Abhari from Imperial College London cautioned that while estimates of the global impact provide insight, they should be viewed carefully, as data regarding infection-related deaths and obesity can often be inaccurate, particularly in lower-resource nations.