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Action on Salt

Associations between body-mass index and COVID-19 severity in 6·9 million people in England


It isn't only those living with obesity who face a higher risk of severe illness or death from COVID-19. In fact, this risk already starts to increase at what is considered a healthy weight, at a body mass index (BMI) of 23 kg/m2.

Taking the height of an average adult in England (5ft 9in for men and 5ft 3in for women), a BMI of 23 corresponds to a body weight of 11.1 stone for men and 9.5 stone for women.

About three-quarter of adults in England have a BMI of 23 and above.*

Any increase in weight above a BMI of 23 increases the risk for severe COVID-19 outcome, regardless of socio-economic status. The more extra weight there is, the greater the risk, even when there are no underlying health conditions. This is especially true for younger adults and Black people.

These findings come from the first large-scale population study that has looked at how body weight influences COVID-19 outcomes across the full range of BMI. The study authors used anonymous health records from almost 7 million adults in England.

Weight is one of the most important modifiable risk factors for COVID-19 identified so far.

What we eat is influenced by our environment, and we are surrounded by cheap, processed foods. Government must now enforce measures to reduce salt, sugar, and saturated fat in unhealthy foods across the board by reformulation, either by setting mandated targets or tiered taxes that strongly encourage industry to reformulate. If such measures had been brought in a long time ago, the toll of COVID-19 could have been less devastating. Any further delay in implementing effective measures to improve the quality of the food available to the nation will cost us many more lives.

*Calculated using the latest Health Survey for England data

Research paper: Gao, M., Piernas, C., Astbury, N.M., Hippisley-Cox, J., O'Rahilly, S., Aveyard, P. and Jebb, S.A., 2021. Associations between body-mass index and COVID-19 severity in 6· 9 million people in England: a prospective, community-based, cohort study. The Lancet Diabetes & Endocrinology. Available at :




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