Re: white bread vs wheat bread
Note also that wheat bread is not necessarily any healthier than white bread. You need to find whole wheat (or whole grain) bread. I had been Subwaying for a while and ordering the wheat bread, and finally got around to checking their nutritional information, and sure enough, it's not whole wheat. Basically, wheat flour is just as milled down as white flour, it's just not bleached yet.
However, if you have them pile on the veggies and some nice chicken breast, you're getting a good dose of protein and fiber along with the less-than-ideal wheat breat, so you're probably not doing too badly.