California, San Francisco, the reason exercise treats obesity is not because it “burns” calories. “That’s ridiculous,” he says. “Twenty minutes of jogging is one chocolate chip cookie. I mean, you can’t do it. One Big Mac requires three hours of vigorous exercise to burn off. That’s not the reason exercise is important.”548 Exercise is important because it generates signals to build muscle—or bone or other lean tissues—instead of unwanted fat.
