When Jennifer Lawrence flaunted her incredibly toned body at the Oscars on Sunday, there was at least person cheering her on: her former trainer, Dalton Wong. The two met five years ago on the set of X-Men: First Class; Dalton helped her get into superhero shape for her role as Mystique. The lessons he taught her stayed with her, and she thanks him for that in the foreword for his new book, The Feelgood Plan: Happier, Healthier & Slimmer in 15 Minutes a Day. “He changed my body for that movie but gave me the skills to change my life,” she writes. “We remain good friends; when I’m in London I love to train in his gym, then afterwards we go out for burgers and fries with his family. It’s all about balance.” Dalton spoke to Cosmopolitan.com to share the secret to J.Law’s amazing look.