All I know is this:
when my kids are hitting growth-spurts... they eat a ton and get hungry frequently. I let them eat.
They even get hungry even 10 minutes after a meal.
I don't feed junk nor have junk in the house, so its fine.
They are both lean, healthy kids, who grow like weeds.
Our Ped said its fine.
One summer, ALL summer, my daughter was like that. After summer, I swear, she must've grown like 5 inches! And her feet too!
It is a growth-spurt.
I can pretty much, guarantee that.
My kids eat their meals and they snack too. They need it. And per my daughter, she needs to snack because if not, her blood-sugar levels drop and she gets mega, fussy.
I don't have a deadline, by which they have to eat, or cannot eat.
My kids only eat, per their body's cues. Hungry or full. They do not eat, for emotional reasons or due to boredom. So I know... when they say they are hungry, they are.
They are healthy eaters.