American Bulldog puppies need to be disciplined as far as eating habits go. Free feeding is when enough dry food is provided and left all day, for the puppy to eat as and when it wants. American Bulldog training does not recommend this type of eating habit.
The second eating habit develops because of scheduled feeding. In this case, a bowl of food is given to the puppy and left for a period of 30 minutes, after which period it is taken away. When the puppy is used to scheduled feeding, it helps to potty train the puppy; and you can lead him to the designated potty place at fixed times during the day. This way the puppy learns bowel control and will wait till you lead him to the potty place to eliminate.
In addition, this scheduled feeding will help avoid eating disorders as well as obesity. As your puppy grows, the vet can recommend the food that the puppy needs as well as chart out alternate feeding schedules, which he deems is right for the puppy.