California Code, Penal Code - PEN § 310.2

(a) Any coach, trainer, or other person acting in an official or nonofficial capacity as an adult supervisor for an athletic team consisting of minors under the age of 18 who sells, gives, or otherwise furnishes to any member of that team a diuretic, diet pill, or laxative with the intent that it be consumed, injected, or administered for any nonmedical purpose such as loss of weight or altering the body in any way related to participation on the team or league, is guilty of a misdemeanor.

(b) Subdivision (a) does not apply to a minor's parent or guardian, or any person acting at the written direction of, or with the written consent of, the parent or guardian, if that person is in fact acting with that authority.  Subdivision (a) does not apply to a physician.