I know this may sound old fashioned, but could your child have worms? It is something that we tend to over look these days, until we are faced with the reality of seeing the worms themselves or it gets to the point where the child is waking with an itchy bot or loosing weight.

Worms can cause children to feel hungry at abnormal times of the day and especially at night, thread worms are not the only worms to affect children, though they are the most common, if you have a pet and even if it is wormed regularly your child is still at risk, as children are notorious for forgetting to wash their hands !

Just a thought.

 You might find that just to get back to bed quickly you are giving the child a 'treat'..  ie - a muesli bar, some crackers or something else along the same vein.  Perhaps try cutting up some fruit before you go to bed or having some dinner left over's that you can quickly reheat.

Also remember that water can satisfy hunger for short periods.  So overnight, perhaps just encourage a drink and telling him to wait until breakfast.

Does your child eat well during the day?  Good food and a variety?

Is this a normal occurence?  Maybe your child is going through a growth spurt or maybe just not eating much during the day?