I've lost 18 lbs in 3.5 weeks by cutting down on my food intake.
Been counting calories and eating more small meals all day. Then at dinner time I eat a normal dinner, just smaller amounts. Also, substituted water for all of my drinks. One soda a day is all I do.
I'm a very active fat guy so I don't need to do too much exercise yet. But when I hit 200 lbs I'm going to have to step it up for sure.