Eating, sleeping, and elimination respond to internal cues, not orders and children do what they feel like doing. The problems start when these basic functions must be fitted into the way the rest of the world lives.
Socialization demands that eating, sleeping, and elimination conform to acceptable patterns.
Parents want these functions to conform to their lifestyle as well. Parents get into trouble when they try to force a child to do any of these three things against the child's will . If you want eating problems for life, force a child to eat. Too many homes have a battleground instead of a dining table. Punish a child for not sleeping and see what problems spring to life.