In order to ensure the continuing competence of licensed physicians and surgeons, the board shall adopt and administer standards for the continuing education of those licensees. The board may also set content standards for any educational activity concerning a chronic disease that includes appropriate information on prevention of the chronic disease, and on treatment of patients with the chronic disease, by the application of changes in nutrition and lifestyle behavior. The board shall require each licensed physician and surgeon to demonstrate satisfaction of the continuing education requirements at intervals of not less than four nor more than six years.