I feel more comfortable when I'm lighter - I sleep better, I snore less, I have more endurance when I work out, my arms look better.
What we do during our working hours determines what we have; what we do in our leisure hours determines what we are.
You will encounter many distractions and many temptations to put your goal aside: The security of a job, a wife who wants kids, whatever. But if you hang in there, always following your vision, I have no doubt you will succeed.