Excess body fat and its impact on someone’s immunity and respiratory system could explain why obesity is behind an increased risk in hospitalisation and death from COVID-19.
Public Health England (PHE) analysed existing studies published across the world during the pandemic to assess the relationship between the coronavirus and obesity.
Experts have speculated about how being overweight increases a person’s risk to COVID-19 and are seeking more research on the subject.
A national crackdown has been launched by Boris Johnson to encourage Britons to lose weight.
Obesity is generally caused by a diet which has more calories than the body uses and which eventually results in excess weight being gained. Certain conditions or medications can contribute to weight gain.
The analysis showed that adipose tissue – or body fat – could be more susceptible to infection as it contains high levels of an enzyme which the coronavirus can attach itself to. Having excess fat gives the virus more of a chance to gain access to cells in the body.
Studies suggest that being overweight and so allowing this excess tissue to form has a direct impact on areas including respiratory function, inflammation, blood and immunity – which are crucial in the fight against COVID-19.
Excess fat around the chest is thought to impact on how well the lungs work, reducing their function and the circulating levels of oxygen in the body.
Obese patients with the coronavirus would suffer from increased inflammation, and there would also be the impact on proteins produced in their body which would normally help to regulate the immune system.
The PHE analysis referred to the “stigma and discrimination” experienced by people with obesity and how it can directly hit their health due to a reluctance to seek medical help and so increase their chances of becoming severely ill with COVID-19.
“Such stigma could mean that people living with obesity are reluctant to access healthcare, or may delay seeking care until their disease is more advanced,” stated the report.
“These are important issues, particularly when trying to prevent chronic and infectious disease.”
A survey showed that 63% of adults in England were above a healthy weight, 36% were overweight and 28% were obese.
Men living with being overweight or obese was recorded at 67%, with women at 60%. Studies have recorded similar figures for adults in Wales, Scotland and Northern Ireland.
Overweight or obese patients with COVID-19 were more likely to be hospitalised compared to patients with a healthy weight.
According to the NHS, people with a body mass index (BMI) – which is calculated using a person’s height and weight – of between 18.5 and 24.9 are considered to be healthy.
A figure of 25 to 29.9 means a person is overweight, while 30 to 39.9 is obese. A BMI rating of above 40 is considered severely obese.
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However, the NHS says a “better indication” of excess fat is waist size. It says men with a measurement of 94cm (37in) or more and women with 80cm (31.5in) or more are “more likely to develop obesity-related health problems”.
The PHE analysis said further research was needed on the direct relationship between COVID-19 and obesity as the evidence published during the pandemic had “its limitations”.