I lnew a guy back in early 90s looked like that .he was in mid 40s copeted in drug tested shows always swore he was natty.I heard he failed once for thyroid but never confirmed.Never failed for steroids.he used to do hours on tread mill.We alwas gave him a pass because he passed the tests and like this guy carried very little mass.So who knows but the evidence says he was natty.