From a site documenting a guy's cross-country US ride:
What did you eat?
I ate in a lot of restaurants, diners mostly. Some days I bought ingredients in the morning and constructed lunch out of them later. Between meals I stopped at convenience or grocery stores.
It took a week or so to realize that at a tourer's long, steady and low-intensity pace, I didn't need to confine myself to the high-carb, low-fat items that cyclists claim to prefer when riding hard and fast on their road bikes. After that blessed revelation, I ate whatever I wanted and indeed for several days in Kentucky subsisted nicely on milk and moon pies.
I always had something with me on the bike, if only an emergency Snickers bar wedged between the tent and sleeping bag. Fig Newtons and their spinoffs (Strawberry Newtons, Raspberry Newtons, etc.), bananas and apples were favorite between-town fuels. I always had three or four packages of Ramen noodles or Lipton "Pasta & Noodle" side dishes to boil up on those nights I was camping some distance from a place to eat.
You eat a lot when you're bike touring and it was not uncommon for Rob & me to go into a restaurant, order something like their "Hungry Mother" dinner and then follow it up with another entrée and then dessert. The need to keep ourselves fueled meant that when we were stocking up on food we would reject certain otherwise appealing items on the ground that they contained too few calories. It was an amusing (and welcome!) inversion of normal dietetic habits.