The evidence is clear that obesity is a risk factor for severe covid-19 disease and death.
Studies in the United States have shown that having a BMI over 30—the threshold that defines obesity—increases the risk of being admitted to hospital with covid-19 by 113%, of being admitted to intensive care by 74%, and of dying by 48%. Public Health England reported similar numbers for mortality, with the risk of death from covid-19 increasing by 90% in people with a BMI over 40.
This is irrespective of age, as being overweight or obese is associated with worse outcomes in younger populations as well. People under 60 years old with a BMI between 30 and 34 are twice as likely to be admitted to intensive care with covid-19 than those with a lower BMI. A report from the World Obesity Federation published on 4 March 2021 showed further trends, emphasizing that death rates from covid-19 have been ten times higher in countries where more than half of the population is obese. And as the world becomes optimistic about vaccines helping us return to some form of normality, a preprint published in February reports that obesity might correlate with a lower immune response to the Pfizer-BioNtech covid-19 vaccine, although the study was small and is yet to be peer-reviewed. These worrying developments have brought much-needed attention to the world’s obesity epidemic.