It never fails...

It all depends on our body's metabolism. Our metabolism determines our hunger and how fast our body process the food that we had eaten and how fast our energy is being burnt out! Most children have higher metabolism than adults. It's no wonder they get hungry faster than adults as their bodies burn off energy from the food they eat faster than adults burn them! I remember in my teens years, I have a friend who has a very high metabolism, and she have at least 5 meals in a day with a lot of snacking every half hour or so.. and still she feels hungry in the class! Even with the way she is eating, she still stays skinny and was severely underweight! Her body was simply burning off energy much faster than she can take in, and she gets skinnier and skinner each day. But for me, I have a very low metabolism drive. I can just eat one meal in a day and feel very full for the rest of the day.. and I won't get hungry at all. So it all depends on how fast your body process energy.

How old are your kids? If they're teenage boys, then not until they're 18 and raiding someone else's fridge. I think it's an unwritten law that entering the house after school requires immediate sustenance. Home = comfort, Food = comfort, school = discomfort. So, after a long day of school, they come home and double up on the comfort at home. Have you thought about having them make some snacks for themselves on the weekend, and then storing them in a kid friendly location. Something simple they could microwave (depending on their age) or just grab that would satisfy them. That way they would have to think ahead about what they want. It would also get them off your back when they got home. By making them involved, they might realize how much goes into making food for them. Also, it would give them something to look forward to which might (heavy emphasis on might) curb their appetite. Good luck.

My son switched schools this year and he doesn't really have as big of a problem anymore. Here's why: they have snack time 2 times a day on top of lunch. So they go to school, have a morning snack, then lunch, then an afternoon snack around 2:30-3pm and he is home by 4:15. Yes, he still wants to eat but the raiding the fridge isn't as bad. He is also in a better mood and seems to be doing better in school (sort of early to tell that though, they have been in since mid-August and missed this last week due to Gustav)

I'm almost never hungry, I don't know why. They're growing kids, some are just like that. Just make sure there are enough healthy things for them to grab or make themselves until you can feed them.