Prime Minister Boris Johnson was so badly affected by coronavirus because he is 'significantly' overweight, an NHS doctor revealed today.

Consultant cardiologist Dr Aseem Malhotra said there is a ten-fold risk of death from the disease - which has so far killed more than 20,000 Britons - if patients are obese.

He pointed out that other 'slimmer' members of the Cabinet - like Health Secretary Matt Hancock - recovered much more quickly and were not hospitalised.

Mr Johnson, 55, has long struggled with his weight and in 2018 revealed he weighed almost 16 and a half stone, which at 5ft 9in puts him in the high risk category.

Other top Government officials and advisers who have recovered from the virus include Chief Medical Officer Chris Whitty, Chief Adviser Dominic Cummings and Health Minister Nadine Dorries.

Prime Minister Boris Johnson takes part in a Clap For Carers at Downing Street on April 2

Dr Aseem Malhotra (left) said Cabinet ministers such as Matt Hancock (right) made a quicker recovery from Covid-19 than the Prime Minister due to being in a healthier condition

Dr Malhotra, speaking on ITV's Good Morning Britain today, said the Centre for Disease Control and Prevention had discovered there was an alarming link between death rates of COVID-19 and obesity.

He said: 'It was obviously very concerning for the whole nation to see our Prime Minister get admitted to hospital with COVID-19.

'Now it is an observation, but it does fit with the evidence, Boris unfortunately is significantly overweight.

'I used to speak with one of his very senior advisers when he was London Mayor a few years ago who expressed to me personally concerns about his weight.

Chief Medical Officer Chris Whitty (left) and Health Secretary Matt Hancock (right) both tested positive for Covid-19 but they were able to make swift recoveries without being hospitalised

'People with obesity also seem to spread the virus for a much longer period of time and also clearly get sicker.

WHY ARE OBESE PEOPLE MORE AT RISK OF BECOMING VERY ILL FROM COVID-19? Studies have shown obese people are more likely to suffer serious complications or die from infections, such as the flu. Doctors say the immune systems of fat people are constantly ramped up as they try to protect and repair the damage inflammation causes to cells. Using all its energy fending off inflammation means the body's defence system has few resources left to defend against a new infection like COVID-19. Obese people also tend to eat a diet with very little fiber and antioxidants - which keep the immune system healthy - such as fruit and vegetables. Most patients with a BMI of over 40 suffer from breathing problems that range from simple shortness of breath to a potentially life-threatening condition known as obesity hypoventilation syndrome (OHS), Excess weight also makes it more difficult for the diaphragm and lungs to expand and inhale oxygen. Starved of oxygen, organs will begin to fail. These factors may explain why obese people's lungs tend to fail faster when the new coronavirus strikes, compared to a healthy person. COVID-19, which has infected more than 300,000 people worldwide, kills by spreading deep into the lungs and causing complications such as pneumonia. There are several other factors that may increase an obese person's chance of falling seriously ill with coronavirus, including a lack of exercise. Studies have shown that physical activity increases the numbers of certain immune cells that help to bolster immune activity. Clogged up arteries also make it hard for blood carrying immune cells to pass through and repair cells around the body. Obese people are also more likely to suffer diabetes and heart disease - two chronic conditions that drive up coronavirus risk. At that time, there were 194 coronavirus patients in ICU. That number is thought to have soared by hundreds more int he last four days. Advertisement

'If you notice Chris Whitty, Matt Hancock and other members of the Cabinet who got the virus did not get it as badly and they are essentially pretty slim.

'They do not seem to be affected by it the way he was.'

In 2013, when he was 48, Mr Johnson attempted to go on a major health kick before taking part in the first Prudential RideLondon-Surrey 100 cycle sportive.

However, in recent years he is said to have struggled to do strenuous exercise due to issues with his knees.

Dr Malhotra, who is Honorary Consultant Cardiologist at Frimley Park Hospital NHS Foundation Trust said issues like high blood pressure, type two diabetes and heart disease all lead to COVID-19 complications.

He added: 'This is really the elephant in the room.

'The centre of disease control a few weeks ago did an analysis and put out the message that there is likely a ten-fold increase in mortality death rates in people who have conditions linked to obesity which basically include high blood pressure, type two diabetes and heart disease.

'This is really a real problem because it is not being addressed and it is not being tackled head on.

'The reasons for this are two fold. One is excess body fat seems to have an adverse effect when it comes to viral illnesses.

'We know that from the flu you are more likely to get severe illnesses if you are overweight but with COVID-19 it seems to also drive an excessive immune response called ARDS or Acute Respiratory Distress syndrome which unfortunately causes many people to die.'

On March 27, it was announced that Mr Johnson had tested positive for COVID-19. And On April 5, with his symptoms persisting, he was admitted to St Thomas' Hospital in London for tests.

After his condition worsened he was moved to intensive care and fortunately he was then able to leave hospital on April 9.

Dr Malhotra explained that in the UK over half the population is classed as obese or overweight and that could be one reason the country has been hit so hard by the virus.

He said: 'This goes well beyond obesity because what is underlined is something called the metabolic syndrome and to put this in perspective only one in eight people in the U.S and our figures are likely similar in the UK because more than 60 per cent of our population are overweight or obese are actually metabolically healthy.

'When you look at the roots of all of this even pre COVID-19 it is well established now that poor diet is responsible for eleven million deaths per year.'

Dr Malhotra, a Consultant Cardiologist at Frimley Park Hospital, Surrey, explained on ITV's Good Morning Britain today how the Prime Minister's weight impacted his recovery

Obese people have a BMI over thirty which in the UK is around 25 per cent of people.

It comes amid theories that smokers could have some sort of immunity to the coronavirus, with French researchers now giving give nicotine patches to patients and frontline workers in a trial.

Some studies and neurobiologists have shown the proportion of infected smokers is much lower than the rates in the general population because nicotine could stop the coronavirus from teaching certain cells in the body, thereby preventing its spread.

Advice from the World Health Organisation has, however, warned that smoking can increase the risk of contracting Covid-19.