North Korean leader Kim Jong-un has become so fat while in office that his ankles have fractured under his own weight, it was reported.

Kim Jong-un, 31, who has looked increasingly portly since taking power, had to undergo a hospital operation after putting too much strain on his ankles during a gruelling round of official engagements.

The treatment has also been linked to Kim Jong-un’s unexpected failure to attend a recent session of the Supreme People’s Assembly, according to a Pyongyang source who spoke to the Chosun Ilbo newspaper in neighbouring South Korea.

Unlike other members of North Korea’s political elite, for whom a sudden absence from public life often means they have been killed or imprisoned, in Kim Jong-un’s case it is said to be down to weight gain as a result of his unhealthy diet.

Kim Jong-un has become so fat while in office that his ankles have fractured under his own weight

Kim Jong-un is now believed to weigh at least 20 stone as a result of his fondness for heavy drinking and imported Swiss cheese, which he gained a taste for while at school in Switzerland.

His ankle injuries are said to have resulted from a long tour of military bases and factories while wearing shoes decked out with Cuban heels, which boosted his 5ft 9ins height but proved difficult to walk in. He is said to have suffered sprains on both feet first and then compounded the injuries by walking more, leading to the fractures.

Bodyguards have been posted around the ward of a Pyongyang hospital where he is now being treated.

There was also speculation that a team of private European doctors had flown in to treat him.

Kim Jong-un’s absence from the assembly was followed by a rare admission by state television which not only showed footage of him limping but also stated that he was ill.

[youtube E0irz3KXSj8 650]