Japan and the sumo diet

Travelling Japan and Korea was a wonderful experience - magnificent sights, great food, interesting people and of course, of interest to this blog, science.I have finally put together the Japan / Korea podcast, which you can listen to here. It was recorded whilst we travelled from Tokyo to Fukuoka on the shinkansen (bullet train), Fukuoka to Busan in Korea on the JR Beetle (ferry), and Busan to Seoul on the KTX (high-speed train) - all fantastic methods of transport that put Aussie transport links (and for that matter UK ones) to shame.The first topic we tackled was the Sumo Diet - how do Sumo Wrestlers get so big? And why? We were lucky to catch the September Grand Sumo Tournament in Tokyo and I was astounded by how big and strong these guys are. What's their secret to rapid weight gain?