The Link Between Obesity And Covid-19, Explained

The UK government has announced measures to get the nation "fit and healthy" ahead of winter.

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Tackling the obesity “time bomb” has become a priority in the fight against Covid-19, with the UK government announcing a raft of new measures to get the nation “fit and healthy ahead of winter”.

As part of a new campaign to help people “lose weight, get active and eat better”, the government will ban TV and online adverts for food high in fat, sugar and salt before 9pm.

It will also end supermarket deals like ‘buy one get one free’ on food high in salt, sugar and fat; and calories will be displayed on menus in restaurants to help people make healthier choices when eating out.

Prime minister Boris Johnson said of the new strategy: “Losing weight is hard but with some small changes we can all feel fitter and healthier. If we all do our bit, we can reduce our health risks and protect ourselves against coronavirus – as well as taking pressure off the NHS.”

The new measures from the government have been met with mixed reaction. While some public health experts believe it’s a step in the right direction, mental health campaigners worry that focusing on weight loss and calorie counting will increase stigma and put those vulnerable to developing an eating disorder or those currently experiencing an eating disorder at risk.

Tim Rycroft, chief operating officer at the Food and Drink Federation, said the move will likely increase food prices, reduce consumer choice and threaten jobs. “Government is pulling [us] in different directions,” he said. “From August the Chancellor is paying for people to eat out, whilst the Health Secretary is proposing banning promotions on the same foods in supermarkets.”

Obesity UK welcomed the new focus, but cautioned against some of the messaging, including the simplistic rhetoric of “eat less, move more”. “Unfortunately, a large part of the government’s strategy plays into this narrative and, as a consequence, may lead to further stigma and discrimination that people living with obesity experience on a daily basis,” the charity said.

“[It] may lead to further stigma and discrimination that people living with obesity experience on a daily basis.”

- Obesity UK

The charity is also “surprised” to see no commitment of funding in supporting those with obesity. It’s urging the government to reconsider the strategy, to include measures for people living with obesity, such as: increased access to treatment options; legislation to prevent weight stigma and discrimination; and a public awareness campaign around the complexities of obesity.

Considering the strategy has been unveiled as a way to beat coronavirus, what do we know about the link between obesity and Covid-19?

What is obesity?

Obesity impacts one in four adults and one in five children, and is characterised by abnormal or excessive fat in the body that presents a risk to people’s health. Those impacted tend to have a higher than average body mass index (BMI) – 25 to 29.9 is classed as ‘overweight’, 30 to 39.9 is classed as ‘obese’, and 40 or above as ‘severely obese’.

But BMI can’t measure obesity alone, as some muscular people have a high BMI without having much body fat. Generally, men with a waist size of 94cm or more and women with a waist size of 80cm or more are considered more likely to develop obesity-related health problems, says the NHS.

There are hundreds of factors that can contribute to weight gain, some of which are out of a person’s control – for example, underlying health conditions, factors in a person’s environment (like poverty), and genetics.

What do we know about obesity and Covid-19?

Obesity has been linked to an increased likelihood of being admitted to an intensive care unit (ICU) with serious complications related to Covid-19. We also know that while young people tend to swerve the more severe effects of Covid-19, young obese people do not.

In the UK, nearly 8% of critically ill patients with Covid-19 in intensive care units have been morbidly obese, compared with 2.9% of the general population.

Individuals with a BMI greater than 35 – particularly those with heart disease – are at high risk for severe Covid‐19, one study found. Obese patients should be the focus of streamlined prevention and treatment strategies, researchers said.

The reason why obesity is a particular risk factor isn’t fully understood and more research is needed. But cardiologist David Kass, who works at Johns Hopkins Hospital in Baltimore and co-led a study that linked higher BMI to more severe cases of Covid-19, has a few theories.

One of them is to do with inflammation, caused by fat itself. Fat cells release signals, which the immune system responds to, and this produces a “low level of background inflammation,” he said. We already know Covid-19 can cause the immune system to go into overdrive and attack itself – known as a cytokine storm – so this may be even worse for someone who is obese.

Dr Karen Coulman, a dietitian and research fellow at the University of Bristol, agrees that the risk of complications “may be due to increased inflammation and changes to the normal immune response in the bodies of people carrying excess weight”.

“Obesity is a complex chronic disease caused by genetic, environmental, social, cultural, and individual factors.”

- Dr Karen Coulman

Kass is also interested in the role of something called the ‘ACE2 protein’ in fat cells. This protein enables the virus to intercept the cells – the virus binds to it in order to gain entry into a cell and infect it.

“It turns out, fat cells express ACE2 at fairly high levels,” explains Kass, “and there’s some past data on this idea related to other respiratory viruses that they can attack fat, last in fat, and shed more slowly from fat.”

What can you do about it?

Obesity isn’t simply an individual lifestyle choice which can be reversed overnight, says Dr Coulman. “It’s a complex chronic disease caused by genetic, environmental, social, cultural, and individual factors.”

The NHS suggests the best way to treat obesity is to eat a healthy, reduced-calorie diet and exercise regularly – it’s recommended you do 150 to 300 minutes (2.5 to 5 hours) a week.

A study of 18,400 adults in China, aged 30-70 years old, found jogging was best for helping people maintain a healthy weight if they had a genetic link to obesity, followed by mountain climbing, walking, power-walking, dancing, and a longer practice of yoga.

The importance of good nutrition also can’t be underestimated in the fight against Covid-19. Professor Daniel Altmann, from the Department of Medicine at Imperial College London, previously told HuffPost UK good nutrition tends to correlate with a healthy, functioning immune system; while poor nutrition correlates with the opposite.

Immunologist Dr Jenna Macciochi also urged people to adopt a healthier lifestyle if they want to help their immune system in the coming months. “It’s all about the small, long term habits,” she said. “Be a regular exerciser, eat a diverse plant-rich diet with lots of fibre and phytonutrients, and get adequate protein and healthy fats. Don’t over or under consume calories, make sure to get enough sleep, and don’t overuse antibiotics.”

Dr Coulman says there’s a need for effective clinical treatments for those already living with obesity. There’s no “one magic solution” to achieving weight loss, she adds, and people living with obesity are encouraged to seek advice from their health providers about the support available to them.