Well, I haven't lost half my body weight, but I have lost 35 lbs. For what it's worth, here's how I've done it: logging EVERYTHING I eat and counting calories using an on-line food diary. This is the single most important thing for me. I know some people can do it without keeping a calorie log, but as soon as I stop keeping track of my calories I start gaining. It's sometimes a pain the neck, but it's vital for me to do it. It's so easy to go over by 200 or 300 calories a day and that's all it takes for me to start gaining again!
I'm consuming approx. 1600 calories a day, which I find is easier to do than an extremely low cal diet where I might lose faster but probably wouldn't stick to for long. I try not to eat too many "empty" carbs like white flour, rice and sugar. I don't eat too many processed foods and when we eat out I always take half home (two meals for the price of one!)
I work out 3x a week at Curves. I get a lot of good ideas and support from this forum.
I have been stalled for a few weeks, but this has happened before and then I'll suddenly lose two or three pounds. I don't lose at the same rate each week like some people. This can be a bit frustrating, but I know that if I keep on plan I will eventually start losing again.
Wishing you success in your weight loss efforts