The Fast is the fourth episode of season three of Three's Company, and the thirty-fifth overall episode of the series. Directed by Dave Powers, it first aired 3 October 1978 on ABC.
Summary[]
Janet believes that Jack and Chrissy lack willpower. Therefore, Janet wagers with Jack and Chrissy as to which one can go longest without their vice: women for Jack and snacking for Chrissy. Jack tries to hold off on his dates and Chrissy fasts, consuming nothing but water. This later proves a challenge for both of them as Grace, a girl whom Jack has been dating, shows up at the apartment, and Chrissy is tempted with a piece of chocolate cake from Jack.