Former foreign secretary Boris Johnson has said a “national weakness of will” is costing taxpayers’ tens of billions of pounds in dealing with the consequences of obesity.

Mr Johnson, who has dropped 12 pounds in two weeks after receiving a wake-up call about his health, said society expected the state to pay for the results of being overweight.

The prominent Tory said a visit to the doctor made him feel “ashamed” and led him to decide to cut down on alcohol and “late night binges of chorizo and cheese”.

A man's beer belly
Boris Johnson has raised the issue of obesity in a piece for The Spectator (Andrew Gray/PA)

The former Cabinet minister said he was a living embodiment of a state of akrasia – acting against better judgment through weakness of will.

Writing in The Spectator, Mr Johnson said: “Here I was, a representative of the political class of what is now the fattest nation in Europe and a living embodiment of our state of moral akrasia.

“Our kids are now so fat that asthma is on the rise.

“Their parents are so obese that they are starting to die earlier – for the first time this century – than the previous generation.

“We are spending tens of billions of taxpayers’ money on the consequences of this national weakness of will.

“We expect the state to pay for all the premature cancers and cardiovascular diseases we contract as a result of our obesity, to say nothing of stapling our stomachs and liposuctioning our thighs.”

Mr Johnson used the situation as an analogy for Brexit.

He said: “We have every possible incentive to change, to get a grip, to go for a different and more rewarding and more fulfilling lifestyle.

“But we are sunk in inertia – a moral inertia that exactly corresponds to the political inertia of the British ruling class.

“We know that we have to make certain changes if we are to leave the EU.

“We know that we have to get ready – to be lighter on our feet and more agile, if we are to take advantage of all the freedoms we will gain: the freedom to innovate, the freedom to regulate in the interests of UK firms, the freedom to open up new markets around the world to British goods and services.

“We have known for two-and-a-half years that we need to make these modest changes.

“And what have we done?

“Nothing. We have been unable to kick our habits, too paralysed, slothful and feeble to leave the customs union and single market, even though it means we are now set to be an effective colony of the EU.”

A broken Union flag in the foreground of the EU flag
Johnson compared Britain’s struggle with obesity to Brexit (Yui Mok/PA)

Mr Johnson said he felt “ashamed” during a visit to a doctor which showed he was 16-and-a-half stone.

Recalling being questioned by the doctor, Mr Johnson said: “What did I eat? I described the delicious late-night binges of chorizo and cheese. She winced.

“How much did I drink? We tried to work it out in units. Glasses, pints, bathfuls? She looked suitably appalled.

“She began to sketch out steps I could take — and I suddenly felt ashamed.”

Mr Johnson added: “I looked at this nice but disapproving French doctor and I resolved, like Gandhi, to be the change I wanted to see.

“I have not only laid off the Mars Bars; I have axed the cheese. I breakfast like some Georgian hermit on porridge with a luxury sprinkling of nuts.

“At drinks parties I guzzle water and marvel at the Pinteresque slowness with which we come to the point. Is it working? You bet it is.”