At my Heaviest I weighed in at 300. I ended up doing weight watchers w/ my wife and dropped 55 lbs in about 3 months.
The thing I like about the weight watchers plan is that you don't have to cut out anything. It teaches you more about eating responsibly than dieting.
As with any diet once you come off of it and start eating like a pig you end up putting the weight on again. I ended up back up to about 275 again and started it up again, dropped 35 lbs and am holding steady as of now.
I always joke w/ my wife that I wanted to come out w/ a diet book and all it would contain is 2 pages
Page 1: Stop eating SH$T all the time!
Page 2: Get off of your A$$ and excercise!
That pretty much says it all
