Obesity Linked to Higher Risk of Severe Infections

Original Article: https://www.medscape.com/viewarticle/obesity-linked-increased-severe-infection-risk-2026a10004bk

The New Findings

A large international study found that people with obesity have a significantly increased risk of serious infections, especially those resulting in hospitalization or death, compared with people of healthy weight. The research included data from more than 540,000 adults followed over many years, showing that people with obesity were about 70% more likely to be hospitalized or die from a range of infectious diseases — such as influenza, COVID-19, pneumonia, gastroenteritis, and urinary tract infections — than those with a normal body mass index (BMI). The risk rose steadily as body weight increased, and people with severe obesity (BMI ≥40 kg/m²) faced about three times the risk of severe infection compared with those at a healthy weight. 

Why It Matters

This study suggests that obesity not only increases the risk of chronic conditions like diabetes and heart disease, but also impairs the body’s defenses against infections, possibly because excess body fat can weaken immune responses and contribute to chronic inflammation. Because obesity rates are rising globally, researchers warn that the number of deaths and hospitalizations from infections linked to obesity could also grow unless more people maintain a healthier weight. 

What Still Isn’t Clear

Although the study found a strong association between obesity and increased infection severity, it doesn’t prove that obesity directly causes infections to be worse. Other factors linked with obesity — such as immune function, metabolic changes, or related health conditions — may contribute to the higher risk. More research is needed to understand the biological mechanisms behind this link and how weight-loss interventions might reduce infection risk over time.