I've been a big guy all my life but I've always been pretty healthy and active. I have no trouble going on hiking trips over mountain trails that are miles long and I can participate well in sports like soccer and Basketball, I'm even a vegetarian.
Being a little over-weight has never really bothered me and it still doesn't but just in the past week I've decided to try and lose more weight. So I have started exercising every day and dieting by eating smaller portions. It seems to be working but I've only been at it about a week so it's a little soon to really be able to tell. Even if I don't lose a lot of weight I figure I'll feel better and be in a better state of fitness.
Starving yourself will have the opposite effect in the long run as your body will compensate by storing fat instead of burning it off. Whoever these people are that are telling you to lay off of salad and chicken are being quite retarded.