I'm living proof that games help you lose weight. At 11 years old I was a genuine couch patato. While being tall for my age (5"11 at the time), I was pretty much obese at 15 stone 10. I'd never been remotely interested in sport, although I did notice when England made the world cup semis in 1990. In 1991 I discovered Sensible Soccer. For the first time in my life I took an interest in sport and started playing football obsessively. I played Real Footy by day and Sensi by night. By 14, I'd hit 13 1/2 stone. By 17 I hit 12 1/2 stone.
At university something went wrong. I left my Amiga at home and bought a PC. It had onboard graphics. I left Sensi behind and stopped playing football. Somewhere in my final uni year I bought a voodoo 3 but it was too late. I was 16 stone and my PC was hopelessly out of date. The next few coulple of years got worse. The weight kept piling on. Around Easter 2003 I bought an Xbox. By summer I'd lost half a stone. My weight kept stable for a while - then in 2004 I built a gaming PC and it gradually came off again. It's been kept up to date ever since with mid to high range components. My gaming has been on-off and the weight has yo-yod at the same time. I put on weight in late 2004. Some would say it has something to do with getting married but coincidentally - I hardly played any games for a few months then.
At my heaviest I hit 19 1/2 stone - then I started gaming regularly again. That was about 2 years ago. Since then I've lost just over a stone and a half and I'm quite muscular with it now (can make the pecs jump and whatnot). So I joined a gym last year, which might have something to do with it. Or maybe it's the games again...