One meal a day. That reminds of a song Groucho Marx used to sing about a family of moochers who ate one meal a day. They started in the morning and finished at night.
Seriously though while your riding hydration is very important. Each individual is a little different. Some will cramp up severely if they don't drink enough. On short rides I usually have a banana before I go. Over fifty miles though packing a banana for the road or bringing an energy bar is a good idea so you don't bonk. If you feel eating a sandwich slows you down, try something a little lighter. Some people will stop and eat half an energy bar for instance. You'll have to experiment a little to find out whats right for you. Bear in mind that your requirements may also change over time and from different conditions. Listen to your body, it will tell you.

Good luck

Jim