Any idea how many calories are in a 64-ounce double gulp soda from a convenience store? 800, how about one of those big cookies? For a society fixated on weight-loss, very few of us know how many calories we’re taking in and what is a calorie, after all? You can’t see taste, or smell them, but they are everywhere. Your brain knows if you’re getting too much or too little. And the more you take in, the more the food industry makes. “Why Calories Count” is not a new diet book, or scheme for losing weight. It’s a book on the science and politics of calories with plenty of fact-based information on interpreting food labels, diet claims, and your own reactions to what the authors call our “eat more” environment. Marion Nestle is a writer and professor of nutrition, food studies and public health at NYU. She and Malden Nesheim, Emeritus professor of nutritional sciences teamed up for the book, their second together.