Sweat, the first floor actually gives diet products. I remember a professional award in the sims 2 was about the army. That can train children to lose weight. In fact, as long as you exercise, you can lose weight. You can let them play ball and swim.
In addition, enter cheating Boolprop test cheating enabled true, and then click the character. There should be an option called get thin to lose weight.
Remember not to let the villain eat until he is full.