The Biggest Loser Season 13 Episode 2 Week 2 ( Air Date 2012-01-10 ) Genre Reality category. Overview "The teams bet on the percentage of weight they think they'll lose in order to gain an advantage at the weigh-in. Elsewhere, the contestants learn to shop for healthful foods; the teams compete in a puzzle-based challenge; and Dr. Huizenga performs sobering health assessments.".