Well your body needs fuel to perform, and it does matter what fuel is used. I recently acquired some Battlebars, which are protein bars. The ones we tried out are what Battlebars calls the MOAB, or "Mother of all Bars". I went ahead and ordered a dozen, and we (myself, my lovely spouse, and our faithful protector) tried one out yesterday. It was actually pretty good....definitely edible. Each bar is 2.47 ounces, and it will provide 25 grams of protein and 250 calories. The MOABs are essentially like a rice-crispie bar with a light coating of chocolate. I'd say one bar would be plenty filling.
My spouse said they were pleasantly crisp, and it tasted good. The dog just wolfed her morsel down with any comments or second thoughts.
Battlebars are produced by a veteran owned company. The bars themselves would be suitable for a BOB or even a typical hiking trip. They can be ordered directly from the manufacturer:
https://www.thebattlebars.com/ I guess we'll be ordering some of their blueberry flavored bars in the near future.