Even slight weight loss can hugely increase our Covid-19 survival chances, experts have said.
Leading scientists analysing the virus told a media briefing that Brits should consider doing a bit more exercise to defend against the virus.
One top Cambridge University academic said he believes he only survived coronavirus because he had lost weight before contracting it.
Prof Sir Stephen O’Rahilly, director of the university’s respected MRC Metabolic Diseases Unit, said: “It’s not about trying to drop a trouser size or a dress size.
“You’re looking to try and get improved metabolic health and you can do that with only marginal weight loss.
“Even if you exercise and don’t lose weight, you’ll improve your insulin levels and insulin sensitivity. Now if you add to that a little bit of dietary restraint you will start losing weight.
“I don’t care if you’re losing weight. What I care about is that the fat is disappearing out of your liver, muscle and other tissues, where it’s wreaking havoc.
“So even if you lost nothing, if you shift that fat out of those organs, which you won’t necessarily even see, that’s doing you good.”
Prof O’Rahilly, 62, is one of the world’s leading experts on metabolism and was first to establish that single gene mutations could cause severe obesity.
“I think that everyone who is at risk if they were a bit fitter would do better,” he added.
“I got Covid in April and I survived. I happened to lose lost about 10 kilos in six months before and I suspect if I hadn’t, I probably wouldn’t be here.”
Prof Naveed Sattar, of Glasgow University, said: “The problem at the moment, and I see this in my clinic, a lot of people are struggling.
“They’re not commuting to work. They’re not taking their normal physical activity. They’re a bit anxious.
“They’re overeating, drinking too much. So I think it’s a very tough time at the moment for a lot of people to try and achieve some of this.”
One top immunologist described how the virus - official name SARS-CoV-2 - has developed a unique “evolutionary tactic” enabling it to ravage through human populations.
Prof Paul Lehner, of Cambridge University, said: “The are maximally transmitting the virus while you’re feeling well.
“This is a really brilliant evolutionary tactic of this virus. It allows you to have a viral factor in your nose and you’re feeling completely well.
“So you don’t go to bed, you go out you have a good time and you spread it. It’s evolved so that it switches off our early warning system.”
