First off if you could tell us the following:
-How tall are you?
-Weight (bf% too guess if have to)
-What is your metab like good,normal,crap(were overweight as a kid or have you never had a problem with your weight)
Anyway I'd recommend that you space your meals 4-5 hours apart if your work limits you,which means that you will be eating large meals however this 4-5 hour gap will reduce protein degradation(look up Lyle Mcdonald's protein book or Lanye Norton for info on this).
Your going to want set your marcos (protein,carb and fat intake) your metab will set your marcos so if you have a fast metab then your carbs will be higher then or its slow then your carbs will be lower etc.
Hope this helps.