Obesity increases infection and hospitalisation risks by 70%, reveals new Lancet study

A latest study published in The Lancet shows that people with obesity are much more likely to get infectious diseases, which can lead to serious illness or even death. The study analysed data from over 540,000 adults in Finland and the UK. It found that people who are obese have a 70 per cent higher risk of being hospitalised or dying from infections compared to those with a healthy weight. The study also shows that obesity was linked to about 1 in 10 deaths from infections worldwide, as per 2023 data.

Obesity is excessive body fat, typically measured by body mass index (BMI). A person is considered obese if their BMI is 30 kg/m² or higher.

People with obesity faced higher risks during the Covid-19 pandemic. However, there was little information on the risks posed by other infectious diseases. Researchers recorded participants’ body mass index (BMI) at the start of the study. They followed their health for an average of 14 years. Each year, they tracked hospital visits and deaths from infectious diseases, yielding detailed data for analysis.

Along with influenza and pneumonia, gastrointestinal and urinary tract infections also increase the risks associated with obesity. However, severe health issues like HIV and tuberculosis did not show the same increased risks. The difference in hospitalisation rates is that those with obesity have a 1.8% chance of being hospitalised each year, compared to just 1.1% for those at a healthy weight.

Researchers found that obesity could be linked to about 0.6 million of the 5.4 million deaths from infectious diseases worldwide in 2023. This means that roughly 10.8%, or one in ten deaths, might be related to obesity.

Why does obesity increase infections?

Obesity harms the immune system. And it’s not just about having extra weight. Fat tissue releases substances that trigger low-level inflammation, keeping the body in a constant state of it. Over time, this ongoing inflammation can weaken the immune response, making it harder for the body to fight off infections.

Obesity often leads to other serious health problems, such as type 2 diabetes, high blood pressure, and heart disease. Each of these conditions weakens the immune system, increasing the risk of infection and complications.

What does this mean for India?

India faces a serious problem with infectious diseases like tuberculosis, pneumonia, and diarrhoea. According to the National Family Health Survey, about 1 in 4 adults in India falls into this category. This statistic highlights a concerning trend as our diets and lifestyles are changing quickly. One worrying issue is “hidden obesity”, which means that some people look like they have a normal weight but have a lot of fat around their stomach and may face health risks. This suggests that we may underestimate health risks if we rely solely on a person’s weight or appearance to assess obesity.