Eat like a pig
Eat like a bird
to eat a large amount of food.
to taste very good.
As hungry as a bear
Eat like a horse
very hungry
to eat large quantities of food and/or to eat in an unpleasant manner.
Melt in one's mouth
the amount of food that one takes is greater than what one could possibly eat.
to eat only a small amount of food
One’s eyes are bigger than one’s stomach