It really just all depends. Alot of dogs do well self regulating. Some way overfeed which is not good. I used to free feed and never had problems (except Jackson not eating
enough 
) but we've had really bad ants here this summer that find every morsel of food so I can't keep it down all day anymore. So now he gets 1/4 cup in the morning and 1/4 cup in the evening both times mixed with either wet food or chicken. In the Fall, I may go back to free feeding once ants are gone.