I was a 5'10 242 lbs 16 year old, at 21 years old I was 172 lbs. I am about 179lbs now at my current age. How I personally did it was that diet came first, when I was 16 I used to tell myself 'it's a diet you are supposed to feel hungry' Now I have no idea if that was the right thing to do or not but you have to understand I went from probably 2500 - 3000 cals a day maybe more sometimes, to id say about 1700 to 1800 average but sometimes less. So my stomach was crying to me and I just had to find the will power to not listen to it but of course I had cheats and breaks. I walked more too and tried to do random zumba sessions in my room because I was too self conscious for the gym. Only started going to the gym 2 years ago. I started pretty much purely for looks - I wanted to be more attractive and again I would say only truly in the last few years has that developed into a want to be healthy. I still would say I have a sugar addiction and have never really been too hard on myself (probably why I have never lost that last stone lol). A massive boost was people noticing and giving compliments - I didn't want that to stop. I also had internet friends that I always thought of meeting so I would keep in mind that I wanted to meet them in better shape because I did the classic thing of trying to hide how big I was. I think my main trick was that I never tried so hard that I put myself under extreme stress and therefore I was able to maintain it. Like I just focused on eating less at the start and I didnt over complicate it with I cant eat that or I have to eat this. I didn't start with a hardcore exercise regime either because I think I knew I wouldn't cope.