I lost about about 5 stone over a year several years back (was 17.5st) and have pretty much kept at 12.5 since. I'm a 6'1 guy though so not too bad. I'm probably 1 or 2lbs heavier than that atm as I put on about 4lbs going back home for xmas but have since lost a couple once I got back home and into my routine. I'd know for a few years I'd been putting on the pounds but the thing that kick-started it for me was when the girl in the Chinese said I was there all the time and I was just thinking 'crap, I go to the chippy more than this place'. I was really embarrassed and thought things had to change so decided I had to get a plan together.
For me it wasn't so much an attempt to go on a diet (I did consider the 5:2) but to completely change my diet. My Fitness Pal was a great help in teaching me the calories in all the bits and pieces that I was eating and it was amazing to me the amount of times I thought I was eating healthy I'd have been better going to McDonalds! In the first few months I was pretty much checking everything which didn't have a label as I was walking round the supermarket. I now have a pretty good idea of the calorie count in most foods/drinks and if I don't I do try to check if I'm thinking of buying it in.
I figured if I was going to start trying to control what I eat the only way I was going to do it was to learn to cook and have a large enough repertoire of dishes that I wouldn't get bored. I'm in a fortunate (though not accidental) position in that it doesn't take me too long to get home from work so I do have time to do this and everything I make now is cooked from scratch. I love cooking (not so much washing up!) so have no qualms about spending 20/30 mins preparing my food and then another hour or so cooking. I don't have kids though so appreciate not everyone is in the same position. I do have quicker dishes as sometimes I just need to crash out after a hectic day. I'm also, without being big-headed, now a very good cook which is always great when friends come round but more importantly means I know whatever I make is going to be better than the rather rank chippy round the corner or the so-so Chinese.
I tend to eat very light lunches (with the right bread and cheese I can make a ham & cheese toastie for a measly 255 calories) but have very large dinners. Most of my evening meal is veg but I'm a firm lover of meat & fish and pretty much every meal will have some element of that to it. Anyone who knew me as a kid can't believe how much veg I eat as I was always eating junk food as a kid. I did do a huge amount of sport then (several different sports at county level) so it made no difference. Sadly, it seems as you get older and stop doing so much, it does :) I think this is probably where my bad habits stem from. It really wasn't my parents fault though as, try as they might, I was an incredibly fussy eater. I'm not sure what it is, but nowadays I probably have one of the most varied diets out there and will pretty much give anything a go as long as I get to cook it.
I do tend to eat fairly late (7:30-8) which a lot of people don't recommend but I tend to find I then don't really get tempted to snack. My cupboards are generally bare of snacks anyway and I just usually have a few apples in the fridge. I'm pretty poor at resisting junk food if it's in the cupboards. I do occasionally get tempted to pop out now and then to the 24 hour Costcutter 3 doors down for a pack of crisps but I can usually rely on Sloth to beat Gluttony if that battle starts in my head :) This temptation is a lot easier to manage these days though than when I first started to try and lose weight. In those early days stopping snacking was like giving up ciggies where you had this little voice trying to convince you just one little thing wouldn't hurt.
I can afford to not be too strict now so have no issue going out for a meal and drinks as I know generally I'm in a deficit on any average day which allows me the odd night out. It does still need to be controlled though as a night on the beer and then deciding to order half the stuff in the takeaway (as I tend to do when drunk) generally undoes most of the good work I've done all week. Still, I feel much better and know I'll never let myself get back to the way it was. It really was a lifestyle change more than anything.