Tackling the UK’s obesity problem could better prepare the country for health crises such as the Covid-19 pandemic, Boris Johnson said.

The Prime Minister, who admitted he had previously taken a “very libertarian” approach to people’s weight, said the country would be “happier and fitter” if it could address the problem.

Mr Johnson also insisted he was fit following his period in intensive care with coronavirus.

We certainly must have a care for the health of our population and we will be happier and fitter and more resistant to diseases like Covid if we can tackle obesity

The Prime Minister did not set out how he intended to tackle the problem, insisting “the arguments need to be gone through carefully”.

But reports have suggested that there could be wider availability of fitness and healthy eating programmes and possibly a wider use of bariatric surgery, which includes the fitting of gastric bands.

Mr Johnson, who lost weight while in intensive care, told Times Radio that he had written “embarrassing” articles in the past in which he had taken a “very libertarian stance on obesity”.

He used a 2004 Daily Telegraph column to say that it was people’s “own fat fault” if they were obese and “the more the state tries to take responsibility for the problem, the less soluble the problem will become”.

In his Times Radio interview, Mr Johnson said the UK was “significantly fatter” than most European countries.

He added: “We certainly must have a care for the health of our population and we will be happier and fitter and more resistant to diseases like Covid if we can tackle obesity.”

Mr Johnson said “I don’t think politicians can treat it as irrelevant” as it was “hugely costly for the NHS”.

The Prime Minister, who did press-ups during a Mail On Sunday interview, said “that was to demonstrate that I was fit, or fit-ish”.

He added: “When I came out of hospital I did notice that there were occasional pieces in the papers saying I was looking a bit wraith-like or something.”