Covid-19 has caused millions of deaths globally, and the number keeps on increasing every day. Scientists have found that certain health conditions like obesity increases the risk of death due to Covid-19. There are different reasons why being overweight puts you at risk. The most common reasons are:
•Obese people have a lower immune system. They are more likely to catch a viral and bacterial infection than people with a healthy weight. Also, low immunity reduces their body’s ability to fight off the virus.
•Overweight people generally have a lower lung capacity, making oxygen intake more difficult for them, which can be further affected if they get infected with the coronavirus.
•They have more demand for oxygen compared to people with a normal range BMI. When this demand is not fulfilled, the chances of death increase.
•They are more susceptible to problems like heart failure, high blood pressure etc whereby infection with Covid-19 could put further toll on the body.
In a recent study of almost 17,000 Covid-19 patients, it was found that those with a body mass index (BMI) of more than 30 had a 33% greater risk of death compared with people of healthy body weight. 
Similarly, a further study found that obese people are at more risk of death than people with a healthy BMI. If they have other life-threatening conditions like diabetes, heart issues, etc, then the risk is even greater. 
Do fat cells also play any role?
In a study, researchers found that an enzyme called ACE2 is what coronavirus uses to enter the body cells.  This enzyme is present in a higher amount in fatty tissues, and these tissues are more prevalent in obese people. So, it could be a reason why obese people have a higher chance of acquiring the virus and getting ill due to its infection.
Is there any role of hospital care in this regard?
Overweight people may face more difficulty in hospital intensive care. Handling them can also be a challenge for the hospital staff. It often becomes hard to intubate and scan them because they have excess body fat. Lifting or turning them to relieve breathing is also difficult.
Obesity and Covid-19 vaccine
Now that the Covid-19 vaccine is out, the next question is will it be equally effective across all body sizes? There is no certain answer to this question. However, the Covid-19 vaccine could be less effective for overweight people, similarly to flu vaccination efficacy in those of an obese BMI compared with a normal BMI. Further research needs to be done to find this answer.
1.Features of 16,749 hospitalised UK patients with COVID-19 using the ISARIC WHO Clinical Characterisation Protocol | medRxiv
2.OpenSAFELY: factors associated with COVID-19-related hospital death in the linked electronic health records of 17 million adult NHS patients | medRxiv
3.Risk of COVID‐19 for patients with obesity - Kassir - 2020 - Obesity Reviews - Wiley Online Library