One of the foremost researchers in human metabolism reveals surprising new science behind food and exercise. Right? Wrong. - Pontzer's groundbreaking studies with hunter-gatherer tribes show how exercise doesn't increase our metabolism. This was a brilliant evolutionary strategy to survive in times of famine. Now it seems to doom us to obesity. Refuting such weight-loss hype as paleo, keto, anti-gluten, anti-grain, and even vegan, Pontzer discusses how all diets succeed or fail: For shedding pounds, a calorie is a calorie. Hunter-gatherers like the Hadza move about five hours a day and remain remarkably healthy into old age. But elite athletes can push the body too far, burning calories faster than their bodies can take them in. It may be that the most spectacular athletic feats are the result not just of great training, but of an astonishingly efficient digestive system. - Revealing, irreverent, and always entertaining, Pontzer has written a book that will change how you eat, move, and live.