make a habit out of doing some kind of exercise during the day. then increase it periodically. do stuff to ignore you hunger, i usually deal with hunger pains all morning until like noon or 1pm and then eat. then i don't eat late at night either. eat hi carb food, but you have to use the energy instead of sitting around and letting it turn into fat.

i used to be a little chubby then i got so addicted to the computer and games and stuff that i didn't eat very much, so i got skinny. then i started to work out a lot more to build muscle, it was pretty easy now that i look back but you have to make a mental decision and stick with it.