The USDA recommends that we obtain 15 percent of our total calorie intake from protein, but gives little guidance as to the kind of protein. The average breast-fed baby receives just 1 percent of its total calories from protein and manages to double its birth weight in six months. This is because the protein from breast milk is of a very good quality and easily absorbed. Assuming good-quality protein, 10 percent of calorie intake, or around 35 grams of protein a day, is an optimal intake for most adults, unless pregnant, recovering from surgery, or undertaking large amounts of exercise or heavy manual work.
The current diet trend toward high protein (30 percent of calories), high fat (50 percent of calories), and low carbohydrate (20 percent of calories) provides way more protein than the body needs, let alone fat, and taxes the kidneys heavily.
The best-quality protein foods in terms of amino acid balance include eggs, quinoa, soybeans, meat, fish, beans, and lentils. Animal protein sources tend to contain a lot of undesirable saturated fat. Vegetable protein sources tend to contain additional beneficial complex carbohydrates and are less acid forming (see page the chart in part 9) than meat. It is best to limit meat to three meals a week. It is difficult not to take in enough protein from any diet that includes three meals a day whether vegan, vegetarian, or including meat. Many vegetables, especially “seed” foods like runner beans, peas, corn, and broccoli, contain good levels of protein and help neutralize excess acidity, which can lead to losses of minerals, including calcium—hence the higher risk of osteoporosis among frequent meat eaters.
Eat two daily servings of beans, lentils, quinoa, tofu (soy), “seed” vegetables (such as peas or fava beans), or other vegetable protein, or one small serving of meat, fish, or cheese, or a free-range egg.
Avoid too much animal protein.
Carbohydrate
The main fuel for the body, carbohydrate, comes in two forms: fast releasing, as in sugar, honey, malt, sweets, and most refined foods, and slow releasing, as in whole grains, vegetables, and fresh fruit. The latter foods contain more complex carbohydrate and/or more fiber, both of which help slow down the release of sugar. Fast-releasing carbohydrates tend to give a sudden burst of energy followed by a slump, while slow-releasing carbohydrates provide more sustained energy and are therefore preferable.
Refined foods like sugar and white flour lack the vitamins and minerals needed for the body to use them properly and are best avoided. The perpetual use of fast-releasing carbohydrates can give rise to complex symptoms and health problems. Some fruits, like bananas, dates, and raisins, contain faster-releasing sugars and are best kept to a minimum by people with glucose-related health problems. Slow-releasing carbohydrate foods—fresh fruit, vegetables, legumes, and whole grains—should make up two-thirds of what you eat, or around 65 percent of your total calorie intake. Every day, aim to:
Eat three or more servings of dark green, leafy, and root vegetables, such as watercress, carrots, sweet potatoes, Broccolini, broccoli, Brussels sprouts, spinach, green beans, or peppers, raw or lightly cooked.
Eat three or more servings of fresh fruit, such as apples, pears, bananas, berries, melon, or citrus fruit.
Eat four or more servings of legumes or whole grains such as rice, millet, rye, oats, whole wheat, corn, quinoa or whole-grain bread, or pasta.
Avoid any form of sugar, foods with added sugar, or refined foods.
Fiber
Rural Africans eat about 55 grams of dietary fiber a day compared with the UK average intake of 15 grams, and have the lowest incidence of bowel diseases such as appendicitis, diverticulitis, colitis, and bowel cancer. The ideal intake is not less than 35 grams a day. It is easy to take in this amount of fiber—which absorbs water in the digestive tract, making the food contents bulkier and easier to pass through the body—by eating whole grains, vegetables, fruit, nuts, seeds, lentils, and beans on a daily basis. Fruit and vegetable fiber slows down the absorption of sugar into the blood, helping to maintain good energy levels. Cereal fiber is particularly good at preventing constipation and putrefaction of food, which are underlying causes of many digestive complaints. Diets high in refined foods that are oriented toward meat, eggs, fish, and dairy products will undoubtedly lack fiber.
Eat whole foods—whole grains, lentils, beans, nuts, seeds, fresh fruit, and vegetables.
Avoid refined, and overcooked foods.
Water
Two-thirds of the body consists of water, which is therefore our most important nutrient. The body loses three pints of water a day through the skin, lungs, and gut and via the kidneys as urine, ensuring that toxic substances are eliminated from the body. We also make about a third of a quart of water a day when glucose is “burned” for energy. Therefore, our minimum water intake from food and drink needs to be more than one quart a day. The ideal daily intake is around two quarts. This is best achieved by drinking eight glasses of water a day, including hot drinks.
Fruit and vegetables consist of around 90 percent water. They supply it in a form that is very easy for the body to use, at the same time providing the body with a high percentage of its vitamins and minerals. Four pieces of fruit and four servings of vegetables, amounting to about thirty-nine ounces of these foods, can provide a quart of water, leaving a daily one quart to be taken as water or in the form of diluted juices or herb or fruit teas. Alcohol acts as a diuretic and causes considerable losses of vitamins and minerals, so it doesn’t count in this regard.
Drink six to eight glasses of water a day as water or in diluted juices or herb or fruit teas.
Minimize your intake of alcohol, coffee, and tea.
The nutritional benefits of water are explained more fully in chapter 18.
Vitamins
Although needed in much smaller amounts than fat, protein, or carbohydrate, vitamins are no less important. They “turn on” enzymes, which in turn make all body processes happen. Vitamins are needed to balance hormones, produce energy, boost the immune system, make healthy skin, and protect the arteries; they are vital for the brain, nervous system, and just about every body process. Vitamins A, C, and E are antioxidants; they slow down the aging process and protect the body from cancer, heart disease, and pollution. B and C vitamins are vital for turning food into mental and physical energy. Vitamin D, found in milk, eggs, fish, and meat, helps control calcium balance. It can also be made in the skin in the presence of sunshine. B and C vitamins are most abundant in fresh fruit and vegetables. Vitamin A comes in two forms: retinol, the animal form found in meat, fish, eggs, and dairy products; and beta-carotene, found in red, yellow, and orange fruit and vegetables. Vitamin E is found in seeds, nuts, and their oils and helps protect essential fats from going rancid.
Eat three or more servings of dark green, leafy, and root vegetables, and three or more servings of fresh fruit, plus some nuts or seeds, every day.
Supplement a multivitamin containing at least the following: vitamin A 5,000 IU, vitamin D 200 IU, vitamin E 100 IU, vitamin B1 25 mg, vitamin B2 25 mg, vitamin B3 (niacin) 50 mg, vitamin B5 (pantothenic acid) 50 mg, vitamin B6 50 mg, vitamin B12 10 mcg, folic acid 200 mcg, biotin 50 mcg. Also supplement 1,000 mg of vitamin C a day.
The nutritional benefits of vitamins are explained more fully in chapter 12.
Minerals
Like vitamins, minerals are essential for just about every body process. Calcium, magnesium, and phosphorus help make up the bones and teeth. Nerve signals, vital for the brain and muscles, depend on calcium, magnesium, sodium, and potassium. Oxygen is carried in the blood by an iron compound. Chromium helps control blood sugar levels. Zinc is essential for all body repair, renewal, and development. Selenium and zinc help boost the immune system. Brain function depends on adequate magnesium, manganese, zinc, and other essential minerals. These are but a few of thousands of key roles that minerals play in human health.
We need large daily amounts of calcium and magnesium, which are found in vegetables such as kale, cabbage, and root vegetables. They are also abundant in
nuts and seeds. Calcium alone is found in large quantities in dairy products. Fruit and vegetables provide lots of potassium and small amounts of sodium, which is the right balance. All “seed” foods—which include seeds, nuts, lentils, and dried beans, as well as peas, fava beans, runner beans, and whole grains—are good sources of iron, zinc, manganese, and chromium. Selenium is abundant in nuts, seafood, seaweed, and seeds, especially sesame.
Eat one serving of mineral-rich foods such as kale, cabbage, root vegetables, low-fat dairy products (such as yogurt), seeds, or nuts, as well as plenty of fresh fruit, vegetables, and whole foods such as lentils, beans, and whole grains.
Supplement a multimineral containing at least the following: calcium 100 mg, magnesium 100 mg, iron 10 mg, zinc 10 mg, manganese 2.5 mg, chromium 25 mcg, selenium 25 mcg.
The nutritional benefits of minerals are explained more in chapter 13.
Pure food
Organic, unadulterated whole foods have formed the basis of the human diet through the ages. Only in the twentieth century did we begin to be subjected to countless man-made chemicals in food and in the environment.
One foundation for health is to eat foods that provide exactly the amount of energy required to keep the body in perfect balance. A good deal of energy is wasted in trying to disarm these alien and often toxic chemicals, some of which cannot be eliminated and so accumulate in body tissue. It is now impossible to avoid all these substances, as there is nowhere on this planet that is not contaminated in some way as a result of the by-products of our modern chemical age. Choosing organic foods whenever possible is the nearest we can get to eating a pure diet today. By supporting the movement back to these kinds of foods we are helping to minimize the damage of chemical pollution, which poses a real threat to the future of humanity.
Eating raw, organic food is the most natural and beneficial way to take food into the body. Many foods contain enzymes that help digest them once chewed. Raw food is full of vital phytochemicals (see chapter 17), whose effects on our health may prove as important as those of vitamins and minerals. Cooking food destroys enzymes and reduces the activity of phytochemicals.
Eat organic as much as you can. Make sure that at least half your diet consists of raw fruits and vegetables, whole grains, nuts, and seeds.
Avoid processed food with additives, and cook food as little as possible.
Top ten daily diet tips
8
The Protein Controversy
What words do you associate with protein?… Meat, eggs, cheese, muscles, growth. You have to eat these foods to get enough protein to grow big and strong. The protein in meat is more usable than the protein in plants. If you do muscle-building exercise, you need more protein … Right or wrong? Many myths abound about protein, how much you need and the best food sources.
The word protein itself is derived from protos, a Greek word meaning “first,” since protein is the basic material of all living cells. The human body, for example, contains approximately 65 percent water and 25 percent protein. Protein is made out of nitrogen-containing molecules called amino acids. Some twenty-five different amino acids are pieced together in varying combinations to make different kinds of protein, which form the material for our cells and organs in much the same way that letters make words that combine to form sentences and paragraphs.
From the eight basic amino acids most of the remaining seventeen can be made. These eight are termed essential amino acids and the body cannot function without them, although others are semiessential under certain conditions.
Each of the basic eight deserves its own optimal daily allowance, although these have yet to be set. The balance of these eight amino acids in the protein of any given food determines its quality or usability. So how much protein do you need, and what is the best-quality protein?
Protein—are you getting enough?
Estimates for protein requirement vary depending on whom you speak to. This is not so surprising, since there may be widespread “biochemical individuality.” In some countries, the estimate is as low as 2.5 percent of total calorie intake. The World Health Organization estimates that we need 4.5 percent of total calories from protein, while the U.S. National Research Council adds a safety margin and regards 8 percent as adequate for 95 percent of the population. The World Health Organization builds in a safety margin and recommends around 10 percent of total calories from protein, or about 35 grams of protein a day. The estimated average daily requirement, according to the UK Department of Health, is 36 grams for women and 44 grams for men. If the quality of protein is high, less needs to be eaten. At the other end of the spectrum are very high-protein diets, unwisely recommended for weight loss. These often contain 100 to 200 grams of protein a day. This is much too high.
So which foods provide more than 10 percent of their calories from protein? You may be surprised to learn that virtually every lentil, bean, nut, seed, and grain and most vegetables and fruit provide more than 10 percent protein. In soybeans, 54 percent of the calories come from protein, compared with 26 percent in kidney beans. Grains vary from 16 percent for quinoa to 4 percent for corn. Nuts and seeds range from 21 percent for pumpkin seeds to 12 percent for cashews. Fruit goes from 16 percent for lemons down to 1 percent for apples. Vegetables vary from 49 percent for spinach to 11 percent for potatoes.
The amino acid family. For a protein food source to contain “complete” protein, it must contain the eight essential amino acids. This is what you find in meat, fish, eggs, soybeans, and quinoa. The semiessential amino acids are also found in these foods. Taurine appears to be essential in infancy.
What this means is that if you are eating enough calories you are almost certainly getting enough protein, unless you are living off high-sugar, high-fat junk food. This may come as a surprise, contradicting all we are taught about protein. Yet the fact of the matter is, to quote a team of Harvard scientists investigating vegetarian diets, “It is difficult to obtain a mixed vegetable diet that will produce an appreciable loss of body protein.” But surely animal protein is better quality than plant protein?
Animal or vegetable?
Once again, there are a few surprises. Top of the class is quinoa (pronounced keenwa), a high-protein grain from South America that was a staple food of the Incas and Aztecs. Soybeans also do well. Most vegetables are relatively low in the amino acids methionine and lysine; however, beans and lentils are rich in methionine. Soybeans and quinoa are excellent sources of both lysine and methionine.
Early theories, such as those first expounded by Frances Moore Lappe in her groundbreaking vegetarian cookbook Diet for a Small Planet, suggested that vegetable proteins had to be carefully combined with complementary proteins in order to match the quality of animal proteins. However, we have since learned that careful combining of plant-based proteins is quite unnecessary. As Lappe says in the revised edition of her book, “With a healthy, varied diet, concern about protein complementarity is not necessary for most of us.”
Even so, you can increase the effective quality of the protein you eat by combining foods from different groups so low levels of certain amino acids in one food group are made up by high levels in another. Over a forty-eight-hour period, aim to eat a varied diet across the food groups shown in the illustration below. The combination of rice with lentils, for example, increases the protein value by a third. This is, of course, the basis of the diet in the Indian subcontinent.
Combining foods for more complete protein.
The best protein foods
The best foods to eat for protein are not necessarily those that are highest in protein. The pros and cons of a food’s other nutritional constituents have to be taken into account. A lamb chop, for example, provides 25 percent of total calories as protein and 75 percent as fat, much of which is saturated fat. Half the calories in soybeans come from protein, so they are actually a better source of protein than lamb, but their real advantage is that the rest of the calories come from desirable complex carbohydrates. T
hey also contain no saturated fat. This makes foods made from soy ideal, especially for vegetarians.
The easiest way to eat soy is in the form of tofu, a curd made from the beans. There are many kinds of tofu—soft, hard, marinated, smoked, and braised. Soft tofu can be used to give a creamy texture to soups. Hard tofu can be cubed and used in vegetable stir-fries, stews, and casseroles. Since tofu is quite tasteless, it is best to use it with well-flavored foods or sauces.
Quinoa has been grown in South America for five thousand years and has a long-standing reputation as a source of strength for those working at high altitudes. Called the “mother grain” because of its sustaining properties, it contains protein of a better quality than that of meat. Although known as a grain, quinoa is technically a seed. Like other seeds, it’s rich in essential fats, vitamins, and minerals, providing almost four times as much calcium as wheat, plus extra iron, B vitamins, and vitamin E. Quinoa is also low in fat: the majority of its oil is polyunsaturated, providing essential fatty acids. Quinoa is about as close to a perfect food as you can get.
Quinoa can be found in many health food stores and used as an alternative to rice. To cook it, rinse well, then add two parts water to one of quinoa and boil for fifteen minutes.
Meat
The average person in the U.S. eats over 200 pounds of meat each year. This is 60 pounds above the average annual consumption in the 1950s. The traditional view is that meat is good for you, being high in protein and iron. But the recent BSE (bovine spongiform encephalopathy or “mad cow disease”) scare has fueled a growing concern that modern farming methods have gone too far. Meat consumption is going down as more and more people are becoming vegetarian and vegan. Leaving moral considerations aside, there are a number of safety issues that give cause for genuine concern: they include the use of antibiotics, growth hormones, and pesticide dips.
The New Optimum Nutrition Bible Page 6
