Our now 11yr old swcah daughter is always hungry too!  It has been this way since she could form the words.  "I’m hungry!" It used to drive us nuts!  We thought at first she was just bored or wasnt having enough of the right foods at mealtime.  My husband got so irritated with her saying she was starving all the time he started to mimic her to me.  She on the other hand doesnt have a speedy metabolism and ususally comes in on about the 80th percentile for weight so we worried a little.  She really looks great but we used to have concerns about how the rest of the kids might treat her as a heavier kid and the might not be able to keep up in p.e. or sports.  Kids can sure be mean!  Anyway, a couple years ago my husband had some stomach trouble and the dr put him on Prednisone for a while.  He wanted to eat everything in site.  After that we let her eat whenever she said she was hungry but only allowed certain "free foods". She had to ask to open the fridge, not ask if she could eat.  We explained it was not mealtime and that anything she ate before a meal was only to be cold raw veggies, a piece of fruit or some crackers (what she could fit in one hand).  Now she will go in a get a whole tomato and eat it like its an apple!  She still uses that same rule, makes good choices on her own and although she does go in and cut herself a slice of cheddar on occassion to go with those crackers its ok because its not all the time and she is aware of what she is snacking on and knows she is pushing the rule and will not feel she is sneaking it.  Days she has sports practice or games she gets to have a little more to eat or snack on.  "Off day extras" I tell her is a no-go.  Works for us.  Easier to manage with an older kid.