Please don’t do that to him. Don’t tell him he’s on a diet. He needs to feel accepted for who he is no matter what, specially by his mother. Teach him self love, self care, which includes making the right food choices, taking care of himself, his room, his things, being responsible at school, speaking kindly to himself, generating good thoughts. Teach him to love himself and the rest will follow. Kindly, An overweight kid on diets from age 11 whose self worth and self esteem were destroyed.