An editorial published today in the BMJ argues that the food industry shares the blame not only for the obesity pandemic, but for the severity of COVID-19 disease and its devastating consequences

Researchers at Queen Mary University of London say coronavirus has made tackling the obesity pandemic even more urgent, and call on food industries around the world to immediately stop promoting, and governments to force reformulation of, unhealthy foods and drinks.

Obesity and COVID-19

The prevalence of overweight and obesity has now reached 65-70% in the UK and US adult populations. Obesity is a major cause of high blood pressure, type 2 diabetes, heart disease, stroke and cancer.

According to the authors, increasing evidence indicates that obesity is an independent risk factor for severe illness and death from COVID-19.

In the UK, individuals who were overweight or obese made up 78% of the confirmed COVID-19 infections and 62% of the COVID-19 deaths in hospitals. Linking UK COVID-19 data to that of a population cohort (428,225 participants, 340 confirmed COVID-19 hospital cases) and to electronic health records (17,425,445 participants, 5,683 COVID-19 deaths) have shown a dose-response relationship between excess weight and severity of COVID-19. That is, the more severe the obesity, the more likely the individual is to be hospitalised for COVID-19 and/or die from it.

After factors such as age, sex, ethnicity, and social deprivation were adjusted for, the relative risk of critical illness from COVID-19 increased by 44% for people who were overweight and almost doubled for those with obesity in the cohort study.

Why is obesity a risk for COVID-19?

Several mechanisms could explain the relationship between obesity and COVID-19.

Angiotensin converting enzyme-2 (ACE-2), the enzyme that SARS-CoV-2 (COVID-19) exploits for cell entry, exists in larger quantities in people with obesity. Whether this is the result of higher ACE-2 expression in the fat cells of people with obesity or having more adipose tissue in general (and thus a greater number of ACE-2 expressing cells) is not yet clear.

The adipose tissue of people with obesity may therefore be a potential target and viral reservoir for SARS-CoV-2 before it spreads to other organs, as has proved to be the case for other viruses.

Obesity can also alter immune responses, as has been shown with the influenza virus, leading to weakened host defence and a greater chance of a cytokine storm with COVID-19.

Finally, obesity diminishes lung function through greater resistance in the airways and more difficulty in expanding the lungs. When patients with obesity need to be admitted to intensive care units it is challenging to improve their oxygen saturation levels and ventilate them.

The food industry

The authors suggest that an increase in food poverty, disruptions to supply chains, and panic buying during the COVID-19 pandemic may have limited access to fresh foods, “thus tilting the balance towards a greater consumption of highly processed foods and those with long shelf lives that are usually high in salt, sugar, and saturated fat.” 

They also argue that since the start of the COVID-19 pandemic, the food industry has used the outbreak as a marketing opportunity (for example, by offering pizzas and doughnuts to NHS staff).

They add that despite some progress, such as taxes on sugary drinks, governments have done too little to tackle the obesity epidemic.

Graham MacGregor CBE, co-author and professor of cardiovascular medicine at Barts and The London Hospital, said: "Governments worldwide must seize the opportunity to help people to eat more healthily and enforce measures to restrict the promotion, marketing, and advertising of unhealthy foods and ensure their reformulation to contain far less salt, sugar, and saturated fat."

Feng He, co-author and professor of global health research at the Wolfson Institute of Preventive Medicine added: “The world is facing two pandemics. One immediately, COVID-19 and the other a longer-term crisis with obesity. Clear evidence has emerged that the two pandemics interact. This is a major opportunity for governments and the food industry to prevent unnecessary suffering and death worldwide.”