Talk about a revenge body! Thirty-nine-year-old mom-of-three Kourtney Kardashian is in the best shape of her life, and she’s worked very hard to get there. “I believe we have one life to live, and I would like to live it feeling my best,” says the Keeping Up With the Kardashians star and single mom, who shares kids Mason, 8, Penelope, 6, and Reign, 3, with ex Scott Disick and recently split with 25-year-old model Younes Bendjima. To get extra lean, clean-eating Kourtney, who limits her gluten and dairy intake, went on the popular Keto diet, sticking to three low-carb meals a day that are high in protein and healthy fats (see box at right). “It was a really positive experience for me,” says Kourtney, who advises followers to check with…
