Our goal with kids isn't to get them on the zone, but to get them to think and make good choices about what they eat. Our goal is to teach them very basic concepts, sugar is bad, protein is good and you need to eat some in every meal. Nuts and seeds are good fats. Eat them, don't avoid them. Pasta, white bread, and white rice are not that good for you, stuff that's red, yellow, green and found in the fruit and vegetable aisle is good for you. Eat a lot of it.
Look at your plate, make a fist, eat that much meat every meal; turn your hand over and fill it with nuts and seeds, eat that much good fat, fill the rest of your plate with stuff you found in the fruit and vegetable aisle. Fill your plate this way at every meal, don't eat more.