Further, if a bird consumes a food which is high in calories, it may not be able to eat enough food to be properly nourished. Birds, like all animals, eat to meet their energy requirements. A single food source, provided in sufficient quantity, may provide a bird with its daily energy requirement, while depriving it of its daily nutrient needs. An example of this principle is a cookie. Another problem with table scraps or human foods involves bulk.
Birds are very small animals.
Giving a parrot half an apple is equivalent to a person being given a ten pound head of lettuce to eat. Again, foods which contain high fiber or are high bulk, may fill the bird but not provide adequate nutrients. Foods must be provided in the appropriate amounts and must be balanced for energy in an overall dietary scheme.