I discuss melatonin's effects on sleep & its safety; I segue into the general benefits of sleep and the severely disrupted sleep of the modern Western world, the cost of melatonin use and the benefit (eg. enforcing regular bedtimes), followed by a basic cost-benefit analysis of melatonin concluding that the net profit is large enough to be worth giving it a try barring unusual conditions or very pessimistic safety estimates.
Full essay: http://www.gwern.net/Melatonin
Eat a meal with a family with a single child. In many cases, the parents will spend much of the meal ordering or pleading with the child to eat their food. Then eat a meal with a family with 6 or more children. That probably won't happen.
I do know one kid who really won't eat on his own; if you don't coax him into eating, he won't eat enough. But that's unusual.