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? Well, here's what you need to do:

1. Skip breakfast. Often people who try to loose weight skip breakfast, but it's actually the worst thing you can. After 8 hours of sleep, your body craves food. By depriving your body of food, you keep your metabolic rate low;
2. Exercise on an empty stomach. If you exercise with no food to burn off, your metabolic rate lowers even more in order to conserve the energy you have. This helps increase your muscle but not burn off too many calories. This point is rather open to debate as to whether it works;
   
3. Sleep after eating. After a massive lunch or dinner, have a sleep. This means you wont burn off all those calories you just ate. This is a major factor;
   
4. Eat big in the afternoon and evening. Going to bed with a full stomach makes your body release a rush of insulin, storing some of your previous intake as fat instead of in muscles and organs;
5. Eat in a social atmosphere. An unreferenced report says that when you eat with others, you eat more than 44% more than when alone. I'd believe that.
   

You can find more info on this diet here.

At the heart of the diet is a hearty stew called chankonabe. It is a communal one-pot simmering stock-based casserole, into which you dip chicken, pork, mushrooms, carrots, potatoes, radish, lotus root and onions as if it were a massive meaty fondue (which I guess it is). You can drink the left over stock. Now this doesn't actually sound unhealthy - indeed it actually sounds pretty nutricious, but if you eat a lot of it, and then have a sleep, you can get very big. And they do eat a lot. A wrestler named Takamisugi was revered for eating 65 bowls in a single sitting.

We tackled a number of other topics in the podcast, so tune in. And feel free to leave any comments you like - I would love to hear from you, especially if you have tried the Sumo Diet...

Listen to his podcast here: