One of the things you will find out is that your stomach is easily fooled; it is largely guided by bulk. If you eat a meal consisting of a moderate quantity of lean meat, a very little bread, a heaping dish of turnip greens, and a big slice of watermelon, you will feel fully satisfied, yet you will not have taken in one-third the calory value that you would at an ordinary meal with gravies and dressings and dessert. The bulky kind of food is that for which your system was adapted in the days when it was shaped by nature. You have a large stomach, many times as large as you would have had if you had lived on refined and concentrated foods such as butter, sugar, olive oil, cheese and eggs. You have a long intestinal tract, adapted to slowly digesting foods, and to the work of extracting nutrition from a mass of roughage. You have a very large lower bowel, which Metchnikoff, the Russian scientist, one of the greatest minds who ever examined the problems of health, declares a survival, the relic of a previous stage of evolution, and a source of much disease. The best thing you can do with that lower bowel is to give it lots of hay, as it requires; in other words, to eat the salads and greens which contain cellulose material. This contains no food value, and does not ferment, but fills the lower bowel and stimulates it to activity. If you eat too much food, three things may happen. First, it may not be digested, and in that case it will fill your system with poisons. Second, it may be assimilated, but not burned up by the body. In that case it has to be thrown out by the kidneys or the sweat glands, and this puts upon these organs an extra strain, to which in the long run they may be unequal. Or third, the surplus material may be stored up as fat. This is an old-time trick which nature invented to tide you over the times when food was scarce. If you were a bear, you would naturally want to eat all you could, and be as fat as possible in November, so that you might be able to hunt your prey when you came out from your winter's sleep in April. But you are not a bear, and you expect to eat your regular meals all winter; you have established a system of civilization which makes you certain of your food, and the place where you keep your surplus is in the bank, or sewed up in the mattress, or hidden in your stocking. In other words, a civilized man saves money, and the habit of storing globules of grease in the cells of his body is a survival of an old instinct, and a needless strain upon his health. Not merely does the fat man have to carry all the extra weight around with him, but his body has to keep it and tend it; and what are the effects of this is fully shown by life insurance tables. People who are five or ten per cent over weight have five or ten per cent more chance of dying all the time, while people who are five or ten per cent under weight have five or ten per cent more than the average of life expectation.