A large-scale study just published in the medical journal The Lancet shows that obesity is not only related to cardiovascular disease or diabetes but also significantly increases the risk of serious infectious diseases. Analyzing data from more than 540,000 adults in Finland and the United Kingdom, scientists recorded that obese people have a 70% higher risk of hospitalization or death from infection than people with healthy weight.
Obesity is defined when the body mass index is 30 kg per square meter or more. During an average 14-year monitoring period, the research group recorded an annual hospitalization rate of infections in obese people of 1.8%, compared to 1.1% in the normal weight group. The risk increased significantly with flu, pneumonia, gastrointestinal and urinary tract infections, while no similar trend was seen with viruses that cause immunodeficiency in humans or tuberculosis.
Alarming global mortality burden
It is estimated that in 2023, obesity may be associated with about 600,000 out of a total of 5.4 million deaths from infectious diseases globally, equivalent to more than 10%. This figure makes obesity an important risk factor but has long not been given due attention in disease prevention.
Professor Majid Ezzati, a public health expert at the Public Health School of the Royal College of London, UK, said: "Obesity changes the body's immune response. Chronic inflammation due to excess fat tissue weakens the immune system, increasing the risk of severe progression when infected.
Why does obesity weaken immunity?
Fat tissue is not only a place to store energy but also secretes inflammatory substances. Prolonged inflammation keeps the body in a state of "alarm", disrupting immune response. Obesity is also often accompanied by type 2 diabetes, high blood pressure and cardiovascular disease, factors that continue to increase the risk of complications when contracting infectious diseases.
In many developing countries, including India, the double burden between infectious diseases and increased obesity is posing a major challenge. Worryingly, the situation of "hidden obesity" with high belly fat even if the weight does not exceed the threshold may cause the risk of being underestimated.
Experts emphasize that weight control, proper nutrition and regular exercise not only prevent chronic diseases but also enhance resistance to infectious diseases.
