My daughter is also turning 5 next month and hungry all the time! I keep a lot of fruit washed and ready to go for snacks - apples, grapes, and oranges. I also make more than one vegetable for dinner. If she’s still hungry at dinner, I give her some baby carrots and a little ranch dip. I make sure she gets exercise. We live in a snowy area so we go sledding a few times a week (the walk up the hill is great exercise!) and we have a kids yoga dvd that we do after dinner some nights. We play catch inside with a beach ball. There is a cd called "Kids in motion" that gives you all sorts of fun physical activities - dancing, imitating animals, etc. All my kids (age 4 - 9) have a riot doing that.
My daughter always wants juice or milk but I often give her water instead. I give my other kids 2% milk but I get skim for her. She is still heavier than average but healthy.
Barbara