The human body is genetically designed to eat carbohydrates and other easy to access energy sources. But, it also has the option to run on a multitude of fuel sources and be metabolically flexible when food is not readily available. And in today’s world, access to food created to play on the body’s cravings is plentiful and many of us consistently eat too much. Drew’s guest, Mark Sisson, explains how we can break the carb hungry cycle to become metabolically flexible and feel good. Mark is a 66-year-old endurance athlete dynamo who changed his athletic performance by changing his diet. He is the author of Primal Blueprint and his latest book, Keto for Life which he discusses in this podcast.    If you like the podcast subscribe & review it on iTunes | Stitcher.    Key Takeaways:   [6:39] From scrawny kid to endurance athlete, Mark shares his coming of age story.    [14:40] As a pre-med student Mark realized he needed a bigger platform than ‘local doctor’ to share his love of health and performance.   [16:50] What changing his diet taught Mark about the correlation between performance and nutrition.    [28:45] Mark describes metabolic flexibility, the key premise from his book, Keto for Life.    [46:21] How to transition out of a strict ketogenic diet.    [50:59] Only having healthy foods at home made it easy for Mark’s children to make healthy eating decisions.  Sponsors:    Organifi — Organifi’s Glow is a vegan raspberry lemonade that boosts your body’s collagen production. Use discount code ‘Fit2Fat2Fit’ for 20% off your order.    Generation UCAN — A superstarch to help you maximize your workouts. Use this link for 25% off your first order.    Complete Wellness Supplements — Shop Drew’s hand-formulated, high-quality, pre-workout greens, Keto Meal Replacement with grass-fed collagen, MCT Oil soft-gels and now a keto meal with Birthday Cake flavor. Some products are available through Amazon Prime.   Dry Farm Wines — You can have alcohol on the ketogenic diet. Use this link for a bottle of wine for $.01 with any order   Mentioned in This Episode: Mark’s Daily Apple Keto for Life by Mark Sisson @MarkSissonPrimal on Instagram Single Daddy Daily Podcast — A Collaboration of Drew & Evan DeMarco Fit2Fat2Fit Take the Fit2Fat2Fit Podcast Listener Survey Fit2Fat2Fit on Facebook  @Fit2Fat2Fit on Instagram Fit2Fat2Fit Book  Complete Keto Book Drew on Social Media: @fit2fat2fit Email Drew: Drew@fit2fat2fit.com