As another former OTR driver, there must be some really poor drivers on this site.
Whatever you choose to eat, be able to drop it when you have to do serious driving stuff. I am serious, the mind will try to protect the food as opposed to dropping it to do defensive driving to dodge the all to common maroons on the highways.
Eating while driving isn't a terrible sin. Not paying more attention to your driving than than your food is. To me, dinner is around noon, supper is in the evening when you should stop and eat.