William Donald Kelley

William Donald Kelley (November 1, 1925 – January 30, 2005) was an American orthodontist who developed "non-specific metabolic therapy," an alternative cancer treatment, now known to be ineffective, which he based on his personal belief that "wrong foods [cause] malignancy to grow, while proper foods [allow] natural body defenses to work."

Kelley received no training in oncology; according to Quackwatch, his ideas are "largely speculative and invalid." His therapy is not only ineffective, Quackwatch notes, but also causes people with cancer who take it to die more quickly and have a worse quality of life than those who receive standard treatment, and they can suffer side effects that are serious at the very least and can even actively cause their deaths.