Your diet is the most important factor of how you look. The term "you are what you eat" is the truest there is. Then it's training, sleep, genetics etc.
I eat the occasional treat (like a burger at the bike meet) but all in all I eat very strict. Every 3 hours (waking hours) I'm having at least 30g good quality protein from a variety of sources (fish, lean meat, seeds/pulses etc). I limit carb intake in the evening but during the day I only eat wholegrain carbs and small portions. Very little sugar in my diet but some in the morning to help recover from my run. I do a 3 mile run 5 days a week first thing before brekkie (about 6:30am). It's hard but the results make you feel awesome (plus the wife doesn't complain either).
Yes I am a bit OTT but there is always a happy medium and a way of eating better. Good luck in the endless quest my friend.
