If there's one thing I've learned from messing about with my own weight for fun (went from 8.5 stone to about 12 in a year or two) it's that everyone seems to react differently to various factors.
I found that as soon as I hit my 22nd birthday, my habit of eating a cheesecake every other day was starting to rest on me. Since I decided that I should practice what I preach when it comes to obesity, I decided to start exercising and, for the most part, cut out the cheesecakes. I was already at kind of an advantage because I walk pretty much everywhere (a benefit of living in a heavily built up area) but I added things like weight training to push myself further, which also meant I could be more lenient in terms of my diet.
The main difference in how you seriously lose weight, in my opinion, comes down to which way you wish to suffer: I don't mind putting my body under a lot of strain through exercise but I hate calorie-counting and eating only meticulously planned out meals. This means that, while I use a lot of fresh meat and produce in my meals, I pretty much eat whatever I want, just in moderation, and then I gun it at the gym.
Other people I know just don't like the pain of strenuous exercise (which I completely understand) so they keep their weight in check by monitoring what they eat and just staying active, (eg: try to walk at least a mile a day, even if you've nowhere to go).
The only thing I can say about these methods is progress is a lot slower than the dedicated people I know, (after three years I'm only just starting to develop the physique I desire) but on the plus side, by taking things at my pace I've not got sick of my regime and every time I see new muscle definition or notice my face looking less round it's a great reminder of what I'm trying to achieve.
I don't know if any of this helps, just waffling on about my own habits, really.