The ketogenic diet, currently gaining attention for its effectiveness in treating diabetes, obesity, cancer, Alzheimer’s disease and many other ailments, is a diet therapy in which carbohydrates are restricted and most calories are taken in the form of fat. By drastically reducing the intake of carbohydrates, the glucose normally used as an energy source in the body runs out, and ketones, formed by breaking down fat, are used as an energy source instead. The author, an obstetrician who has treated many pregnant diabetes patients, explains the effectiveness of a ketogenic diet, and demonstrates that “low-carb is best for the health.” In a worldwide first, he reveals that fetuses and babies use ketones as an energy source instead of carbohydrates.