The reason he won't be starved off the 'habit' is because he is getting a huge proportion of his daily calories (presently) in the night. There may be several reasons for this:
He is too busy (himself, or your family life) for him to concentrate on eating enough
He is growing too fast to be able to eat enough during the day
The calorie density of the foods he's eating during the day is too low to carry him through the night
If he's growing normally and otherwise is healthy, it may just work to feed him more, more frequently and higher-calorie choices (like cheese instead of skim milk, or avocados instead of celery sticks) during the day, so he isn't so hungry through the night.
It's not a habit, by the way. It's hunger.