It seems to vary wildly from person to person. I never take anything but water, a few Luna bars, and on longer rides, PB&J. I hate sports drinks, don't like gels much either. I have never bonked. That includes rides ranging from 30 to 200 miles. My spouse, who eats a bunch more than I do on rides, has occasionally bonked--and he is a stronger rider than I am. It's a mystery to me why one person bonks and another doesn't.
My doc, a major athlete, once told me she'd dated a guy on the national Olympic Nutrition Committee, and he said that water and PB&Js pretty much give you what you need. You will now hear from a ton of other people who have totally different approaches, all of which work for them. So I think you will need to start experimenting...I wish there was an easier answer than that.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks