A high protein diet of 16% enables the rabbit to gain bone mass while it is growing, and later in gaining muscle mass. Small amounts of apples, cabbage, or broccoli given as treats and slowly increased do not harm the health of the rabbit; for instance, a rabbit consuming a quarter of an apple every other day can safely be fed half an apple with the same frequency after three weeks. (However, feeding the apple core or seeds to the rabbit may be harmful.) Flemish Giants do not reach full size until they are 1.5 years old, and consume a large amount of food during this time. After females deliver kits, and during winter for all Flemish Giants, the rabbits must be fed as much as they can eat, and given plenty of water.