North Korean state TV said leader Kim Jong Un is suffering from "discomfort," the first official acknowledgment that he is unwell after a period out of the public eye. (Reuters)

In North Korea, political life revolves around Supreme Leader Kim Jong Un. Yet Kim appeared to have skipped a high-level governmental meeting Thursday – and no one seems to know quite why.

Televised footage of the reopening of North Korea's Supreme People’s Assembly did not show Kim at the meeting, the Associated Press reports. South Korean officials tasked with keeping tabs on the North now believe that it is the first time that Kim has missed a meeting at Pyongyang's parliament since his father died in December 2011.

In fact, Kim, usually a focus of North Korean state media, has not been seen since Sept. 3, when he appeared at a concert with his wife.

This absence has sparked much speculation in the South Korean press, with many suggesting that Kim is in poor health: During the summer, North Korean state television showed him walking with a slight limp, which many had taken as a sign of a wider problem at the time. Chosun Ilbo notes that Kim appeared in the North Korean media earlier this week, but it was noted that he was "laboring on" in the heat: Perhaps a reference to fatigue, the South Korean newspaper suggests.

Wilder theories have sprung up further afield. Britain's the Daily Mirror suggests that Kim could have become ill from eating too much imported cheese. The Swiss-educated North Korean leader has developed an infatuation with Emmental cheese, the tabloid reports, and may be suffering ill health due to the weight he has since gained. The Daily Mirror provided no source for this theory.

Other news outlets suggest that security concerns may be a factor. "Another reason why Kim may be reluctant to appear in public is the ongoing power struggle inside the North Korean military, which means that the situation in Pyongyang is still unstable," Toshimitsu Shigemura, a professor at Tokyo's Waseda University, told the Daily Telegraph. Late last year, Kim had his own uncle executed, which many observers took as a sign of a surprising and unusual power struggle in Pyongyang.

Kim's absence is tantalizing, but most North Korean experts are pouring cold water on it: The North Korean leader was absent for two weeks in 2012, NK News notes, and later returned to the public eye with no explanation. And his wife, Ri Sol Ju, went missing for a number of weeks in 2012, prompting speculation that she had fallen out of favor with Kim. It is now believed that she was kept out of the public eye as she was pregnant.

See also: Why no-one really knows what's going on in Kim Jong Un's North Korea