Kim Jong-un's penchant for sushi, Cristal champagne behind his epic weight gain

The former chef of Kim Jong-un's father has revealed that lavish diet of supreme leader, which includes sushi and Cristal champagne, is to be blamed for its epic weight gain.

Kenji Fujimoto, who released the memoir 'I was Kim Jong-il's Cook' based on his 13 years in the former leader's service, also indicated that shark fin soup, a dish which is illegal in the UK, was served during a lavish banquet that he was invited to in 2012, the Independent reported.

There were concerns over the 32-year-old's health in 2014 after he was not seen in public in North Korea for more than a month following reports of ankle surgery.

However, as rumours circulated that the supreme leader was suffering from gout, the country's ambassador to the UK declared that he was healthy.