Without being rude to anyone here, I would say that there are a few that could do with the balance of diet and training. To be perfectly honest, if you want to see real gains you have to control your body fat levels and that can be the most difficult. Infact, I would say its more difficult than the training itself as its harder to be disciplined, especially when you have worked out hard... your body wants to eat!!
I would go as far as to say that training without a decent diet is a complete waste of time. You will not see the gains that you have achieved which in turn will see a lot of people lose there motivation... Its also a bad habit.
Eat right and train properly and you will enjoy much more progress.