Cockatoos are prone to becoming overweight.
Picture from Cockatoo Sanctuary
If their diets aren't carefully monitored, captive pet Cockatoos have been known to gain weight and sometimes become obese. Cockatoo owners are encouraged to offer their birds access to minimal seed and a variety of fresh, bird-safe fruits and vegetables. In addition to restricted seed intake, Cockatoo owners are also cautioned to reserve items such as nuts and breads for treats.