What changes the food answer
Start with the species. A budgie, cockatiel, canary, dove, lorikeet, and macaw do not all eat the same daily diet.
Build around a staple
Many parrots do well with pellets as part of the base diet, while some birds need different seed, soft food, nectar, or fresh-food routines.
Use fresh foods with rules
Offer washed bird-safe greens and vegetables in small portions, introduce one food at a time, and remove wet foods before they spoil.
Keep treats useful
Millet, seeds, nuts, and fruit are best measured and saved for training, foraging, or small rewards.
Watch the bird
Track appetite, weight, droppings, and what actually gets eaten. A full bowl is not proof of a good diet.