Overdoing It is A Help Me Be Good Book by Joy Berry for ages 3 - 7 that explains to children why overindulgence is harmful. It also encourages children to do things in moderation.
Help Me Be Good About Overdoing It is a self-help book for 4-8 year old children. It deals with the behavioral issue of overdoing it and offers practical, down-to-earth advice on ways to overcome this behavior.