As Steve Hendricks shows in this book, stop eating long enough, and you’ll set in motion cellular repairs that can slow aging and prevent and reverse diseases like diabetes and hypertension. Fasting has improved the lives of people with epilepsy, asthma, and arthritis, and has even protected patients from the worst of chemotherapy’s side effects. But for such an elegant and effective treatment, fasting has had a surprisingly long and fraught history. Threaded throughout are Hendricks’s own adventures in fasting, including a stay at a luxurious fasting clinic in Germany and in a more spartan one closer to home in Northern California. This is a playful, insightful, and persuasive exploration of our bodies and when we should—and should not—feed them.