People who seldom eat fruits and vegetables can eat them.
But I think it's better to eat fresh fruits and vegetables. A good appetite is a good thing. You can let him eat an apple about half an hour before meals, and then you can eat less when you eat.
You can also increase his activity and exercise more. Children are generally active and help digestion. Proper exercise is good for your health. Eat more fruits and vegetables, eat some miscellaneous grains and meat, or eat more natural food. Those health products and nutriments are good, but they are all industrial foods, hehe.
Children are still in the development stage, don't lose too much weight, but remember not to eat too much at once, which is easy to get fat and bad for physical development.
It doesn't matter how much you eat, it depends on how you eat, eat more meals a day, eat a little at each meal and exercise more, so this is a good thing. But if you eat a lot at a meal, you are full and don't exercise, then this is not good.