Well, you may not like the answer, but....
the first 20ish lbs took 2 years. But I wasn't consistent with my food. I was also under some life stress, which didn't help me. I'd loose 3 lbs one month, gain 2 the next. That kind of thing. But I kept trying and exercising. I wasn't logging my food. I was just eating too much. My serving sizes were way off.
What really turned it around for me was the Okinawa diet The food is really good, it heavily relies on soy, and it tastes great. In the last 8 weeks I've lost 16 lbs. But I'm logging my food and exercising. But I'm really satisfied for the first time in ages. I can turn down things that aren't healthy for me because I feel so much better.
Hope this helps.