I'm 42 yr old women and since using fitness pal and working out to T25 Shawn T, I've lost 10 lbs in 4 weeks. Most progress I've ever seen.
I've started about a month ago, exercising with very little results, its wasn't until 2 weeks ago I downloaded this app to count my calories that I actually started to lose weight. Woohoo. I lost 3 lbs so far.