... that you shouldn't complain when they don't eat their "proper" meal? 
My friend has a 2.5 yo boy. who is given bread with his meals, a slice at the beginning, then more is summoned if he eats it all. Then mum wonders why he hasn't eaten the rest of his dinner!
Is it just me, or would you think you'd leave the bread out altogether? And then of they have finished their dinner and still want more, then that's the time to bring out the bread? Or just stick with the first piece and don't offer more?