COVID-19 and Body Mass

Unfortunately at this point the majority of scientists agree upon the fact that Covid-19 has become, and will be a part of, our reality for many months if not years to come. During this period, as a society we have been learning and adapting to new measures in our fight against the disease. Quarantines, social distancing, sanitizers in many shapes and forms, as well as some bogus anti-Covid ‘supplements’ are the first ones that come to mind in this long list.

However one of the more significant details that has been recently revealed in numerous research studies is the undeniable connection between an individual’s physical fitness and the severity of Covid-19 disease. To be more exact it is the connection between BMI (Body Mass Index) and the severity of Covid-19 symptoms an individual experiences. And outcomes of these studies indicate that the higher one’s BMI the stronger and fatal the disease becomes.

You might be asking what it is that is causing this adverse reaction to Covid-19 in overweight/obese populations. Stephen O’Rahilly, director of the Medical Research Council’s Metabolic Diseases Unit at the University of Cambridge says “Two things happen when obesity occurs: the amount of fat increases, but also you put fat in the wrong places. You put it in the liver and in skeletal muscle. And that disturbs metabolism. The key disturbance is that you get very high levels of insulin in the blood.”

And he suggests that it is this disturbance that leads to a wide range of abnormalities such as increases in inflammatory cytokines as well as a reduction of adiponectin, a molecule that directly protects the lungs. Stephen O’Rahilly adds that it is also possible that fat could be increasing in the lung itself, which may lead to complications in how the lung handle the Covid-19 virus.

So far studies in the United States have indicated that having a BMI over 30 – a BMI above 30 indicates obesity- increases the risk of being admitted to hospital with Covid-19 by 113%; of being admitted to intensive care by 74%; while increasing the risk of death by 48%. On top of that Public Health England’s report suggests that the increase in risk of death rises by 90% in people with a BMI above 40.

What’s even worse is that these numbers are irrespective of age, as extra weight and obesity tend to affect younger populations just as bad. According to World Obesity Federation people under the age of 60 with a BMI between 30-34 are statistically twice as likely to be admitted to intensive care than those with a lower BMI.

Public Health England also warns that the risk of developing serious disease due to Covid-19 among people from black, Asian, and minority ethnic groups is 2.56 times higher than among white Europeans,. However at a BMI of 25 there is no such difference to be observed between ethnicities.

Considering that obesity is one of the biggest health problems that the UK is currently facing with two-third (63%) of its adult population being overweight and/or obese, this should be seen as a major concern as well as a call for action. We have to understand that avoiding contact with the virus is one part of the battle.

Being prepared for the infection is another part. And knowing that excess weight is a modifiable risk factor, improving your physical fitness is one of the smartest steps you could be taking right now. In addition to becoming more Covid-proof you will also be looking better!

Aydin Parmaksizoglu

BMI Formula: weight (lb) / [height (in)]2 x 703


GOV.UK. 2021. Excess weight can increase risk of serious illness and death from COVID-19. [online] Available at: <; [Accessed 8 June 2021].

Mahase, E., 2020. Covid-19: Why are age and obesity risk factors for serious disease?. BMJ, (371), p.m4130.

Senthilingam, M., 2021. Covid-19 has made the obesity epidemic worse, but failed to ignite enough action. BMJ, p.n411.

Williamson, E., Walker, A., Bhaskaran, K., Bacon, S., Bates, C., Morton, C., Curtis, H., Mehrkar, A., Evans, D., Inglesby, P., Cockburn, J., McDonald, H., MacKenna, B., Tomlinson, L., Douglas, I., Rentsch, C., Mathur, R., Wong, A., Grieve, R., Harrison, D., Forbes, H., Schultze, A., Croker, R., Parry, J., Hester, F., Harper, S., Perera, R., Evans, S., Smeeth, L. and Goldacre, B., 2020. Factors associated with COVID-19-related death using OpenSAFELY. Nature, 584(7821), pp.430-436.

World Obesity Federation. 2021. Obesity and COVID-19: Policy statement | World Obesity Federation. [online] Available at: <; [Accessed 8 June 2021].

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