This is contrary to most of the advice you are getting, but I have found that feeding lots of carbohydrates just lets a person get hungry again faster.
Meat, eggs, milk and cheese will work better at filling you up and staying full.
Looks like
@flowerbug has the same general advice. I remember starting my day off with cereal and toast, and being hungry again by 9am.
I agree so much with this!!!
I raised 3 boys on one pretty low income...considered poverty level, actually. The foods I could afford to feed were mostly starchy foods~pasta, rice, potatoes, etc.
Not so good and it raised boys pretty much addicted to carbs, though they did get VERY healthy meals at their grandparent's who watched them for me while I was at work until they were in their teens...and it was in the teens when you couldn't fill them up, so the starches were the staple, sad to say.
So, my advice is to give nutrient dense proteins and fats, foods high in fiber, if you want to put that appetite to rest and raise a kid that doesn't have problems later in life...my boys are all overweight as I type this..a couple VASTLY overweight.
Eggs, meat, coconut oil, animal fats, olive oil, yogurt(plain has no added sugar and can be used in dips, salad dressings, on top of Mexican foods, etc.), beans are high in fiber, so even though they are carbs they also are so very good for you...so big pots of chili, big pots of chicken soup or veggie beef soup, breads that are easy to make~quick, flat breads that can be fixed and done very shortly that don't contain as much sugar as traditional homemade breads.
Sandwiches are good but try to do them in the form of lettuce wraps, instead of using too much breads.
Cheeses provide fats and protein, so adding them to dishes can increase nutrient density. Tacos, burritoes, Mexican soups...all of these contain cheese, meat, lettuce, onions, tomatoes, peppers and the bread used is very thin and doesn't contain much sugar, if any. And kids LOVE Mexican foods.
Cottage cheese is good if they'll eat it...dress it up with bacon, spices, etc. to make for a great side dish.
Omelettes for breakfast are a big hit and contain all the essentials for a nutrient dense meal and they go great with a low cal flat bread.
Thin crust pizzas with a lot of meat, cheese, and veggies on it...also a more healthy alternative to most of the thick crust or pan style pizzas.
For a great dip there's one involving Hormel chili w/beans or without, cream cheese, shredded taco cheese, and salsa that my boys beg for...actually, anyone who tastes it begs for more. It's just one can of the chili, one pack of cream cheese, cheese, med. salsa and lay it into a casserole style dish in layers and nuke it for 10 min. I add jalapenos too but your boys don't like spicy, so you could change the salsa to mild and leave the jalapenos out.
It's not expensive, you can turn them loose with a bag of tortilla chips and let them go to town on it.
curious George...
That's when I made the bread rule. 
