The case against sugar is a complex one. Besides the fact that refined sugar is a totally unnatural substance that has been stripped of its nutritional value—fiber, vitamins, and minerals—apart from the calories it provides, sugar in concentrated form is very hard on the pancreas. The pancreas, which is responsible for the production of insulin and therefore the regulation of blood sugar and energy levels in the body, has adapted through evolution to deal with a steady flow of glucose in small quantities such as those that result from the intake of complex carbohydrates.
One of the biggest beauty cons of all is the idea that if you eat lots of protein your muscles, skin, hair, and nails will grow strong and you will stay young. Like the old-fashioned high protein diet for building up athletic strength, it doesn't work. The human need for protein has been grossly exaggerated. At the turn of the century, respected opinion held that we need between 120 and 169 grams of protein per day. Then Chittenden showed in human experiments that far better performance and health were possible on fifty grams, a much lower amount. Another scientist named Hindhede set the figure at thirty grams. Then Oomen in Amsterdam and Hipsley in Canberra discovered a population in Australia which develop not only full health, but exceptional muscular structure and performance on a diet of merely 15 to 20 grams of protein per day.
Later in the United States, the American Research Council's Food and Nutrition Board agreed on a daily requirement of 70 grams for adults. One member of the board, named Sherman, described how this figure was arrived at. The evidence the committee examined indicated that a much lower amount was needed, somewhere around 35 grams, but there was agreement that if so low a figure had been set there would have been a public outcry, so a corresponding "margin of safety" was decided on and the 70-gram figure was published. But because the scientific basis for the figure was nonexistent, the word "recommendation" was chosen instead of "requirement." Current recommendations for protein intake hover about the 50-gram mark, although there is strong evidence now that we probably need even less.
Your body needs amino acids, the constituents of protein, for its metabolic processes, for growth and the repair and maintenance of body tissue. Proteins are made up of twenty-two different amino acids; all but eight of them your body can manufacture itself. These eight, which have to be taken in through your foods, are referred to as "essential" amino acids.
A large portion of a protein molecule is made up of nitrogen, and one of the important things about taking protein is that it helps keep a good nitrogen balance in the body, so there is as much nitrogen coming into the body as there is leaving it. This balance helps maintain body health and muscle strength, so that you don't go into what is known as a negative nitrogen balance, when you lose muscle tissue from your body. To keep your nitrogen right, 10 to 15 percent of your total calorie intake should be from protein.
But when a greater percentage than this of your calorie intake comes from protein foods, then your body goes into a negative mineral balance and you start gradually losing precious minerals and trace elements such as zinc, calcium, magnesium, iron, potassium, and chromium from your system. These nutrients, so easily lost from the body, are vital not only to physical health but also to emotional stability and well-being (more about minerals later). Wachmann and Bernstein of the Department of Nutrition at Harvard University investigated the high protein diet and came to the conclusion that the protein-rich (especially the meat-heavy) diet plays a strong role in the genesis of osteoporosis, a softening of the bones, particularly in women after menopause, caused by the loss of minerals. This is probably because of the high protein diet's tendency to leach valuable minerals (in this case calcium) from the system. And purely from the point of view of physical beauty, many of these lost minerals, such as sulfur, selenium, zinc. magnesium, and calcium, can make the difference between prematurely aging skin caused by a rapid collagen and elastin breakdown, nails that split, or hair in poor condition, and radiant looks glowing with strength and health.
Finally, the breakdown and metabolism of proteins in the body lead to the formation of a number of complex by-products such as urea, nitrogen, and ammonia, which can be toxic. These wastes need to be eliminated. This isn't always easy, and it puts great strain on the liver and kidneys. This is why, on the well-known high protein reducing diets, you are advised to drink large amounts of water in order to water down these poisons and help excrete them.