Muscle work, 25, 30 and carbohydrates, 40 and diet, 17 and fasting, 17 and protein, 18 and undernutrition, 38, 39 Occupation and metabolism, carrying a load, 31 climbing, 32 industrial, 33 posture, 30 running, 30-32 walking, 30 Oleomargarine, 12 Olive oil, 8 Overfat people, 38 Oxidation of food-stuffs, 24 Peanut butter, 12 Pellagra, 9 Pork, economic production of, 19, 20, 21 Potato diet, 15 Rules of saving and safety, 43 Substitution of foods, 43 historical, 11 Summary, 43 Surface area and heat production, 26 Undernutrition, 38 and labor, 38 Vegetable oils, use of, 12 Vegetarianism, 16 Vitamins, 8, 23 Weight, reduction of, 39 Women, metabolism of, 27