The health of North Korean leader Kim Jong Un has long been a source of morbid fascination in rival South Korea, which sits in the shadow of Kim's 1.2-million-strong army and his growing arsenal of nuclear-armed missiles. Has he gained even more weight? Is he struggling for breath after relatively short walks? What about that cane? Why did he miss that important state anniversary? Now, the 37-year-old faces fresh speculation in the South about his health again. But this time, it's because he's noticeably slimmer.