About 80 pounds--how I did it
Briefly--50 yo male, overweight, family history of diabetes, etc. Tried off and on to lose weight with varying success. Something (I don't know what) finally clicked for me, so back in August, I began using FitDay, to log my activities and my intake. The key for me has been being RIGOROUS about logging in EVERYTHING that passes my lips. I also bought an inexpensive food scale, to really accurately measure my portions (in the past I just estimated).
I also began walking for 20 - 25 minutes each morning, and after about a month added the same amount of time on an old exercise bike that has been gathering dust. I also really changed the way I eat--lots more fresh foods, vegetables, citrus fruits, etc. Basically eliminated most breads (except for light wheat) and pastas (very small amounts). Cooked a lot from CookingLight; never felt like I was starving, either, even though I was eating only about 1000-1200 calories a day (might not be recommended for most people).
And it's worked. From a start of 258, I'm down to about 180 right now. Feel great, more active, new clothes, more confident--all the good stuff. I have in the last few weeks added some free weights and some resistance bands to tone up and build some muscle. My wife is very happy also!
So--be rigorous (obssessed almost) and honest and watch your portions--it will work for you too.