Having achieved enlightenment in the critically acclaimed The Year of Living Biblically and sharpened his mind in The Know-It-All, bestselling author A.J. Jacobs had one feat left in the self-improvement trinity: to make over his body and become the healthiest person in the world. He assembled a team of expert medical advisers. He pledged to disentangle medical myths from reality. Then, over the course of two years, he subjected himself to a grueling but entertaining regimen of exercise, diets and experiments that yielded surprising insights—and tested the patience of his long-suffering wife.