Well, my retired bettas eat pellet food most of the time, but get treats whenever I have leftovers.
For a normal diet for my breeders, I feed them as wide of a variety as I can come up with. I feed them cucumbers, shelled peas, boiled egg yolks, etc. For conditioning I feed them less vegies and more live food such as mosquito larvae and those little water fea thinks. They love those!!! And occasionaly they get a treat of yonge brine shrimp. I feed them this 2-3 times a day depending on their weight and personal prefered diet.