Want to lose weight? Eat less. Don't believe me? Go get your stomach stapled.
DING DING DING!!!! WE HAVE A WINNER!!!!
It amazes me that with the myriad of weight-loss schemes out there, simply eating smaller portions seems to receive so little mention. I guess there's no money to be made in eating less food!
Eating less of whatever you want coupled with even a minimal amount of physical exertion will do wonders.