I eat in restaurants when I can, but I carry food in my handlebar bag. The larder that I always have is
Couscous
2 x Ramen
4 x instant oatmeal
Energy bars/candy
Dried fruit and nuts
Earl Grey tea bags
this is enough food (once hydrated) to keep me going for 2 days.
in jersey pockets usually bananas or apples and more energy bars.
If there's a long stretch without resupply I'll add tortillas, cheese and salami which I stuff in the food bag in my handlebar bag.
If I stop at a supermarket at night I carry bigger items like cans of soup, beans, pizza etc under the saddlebag longflap. I have also use that method to carry a couple of extra liters of water. There's also room in the handlebar bag for a small bottle of soda, but that generally just goes in my back jersey pocket along with the candy and bananas. If I need even more carrying capacity I have a 2oz nylon backpack.