I was 35 pounds overweight. Saw the writing on the wall and in three months I'm down 25-30 pounds. Stopped eating sugar and bread and only eat one meal 2-4 times a week.
The trick is to keep that going in the longterm. I did manage to lose that amount of weight in the same amount of time as well, but ended up gaining it back in under 5 years, which I hear is the fate of most people who lose weight.