Guidelines for Healthy Nutrition define the structure upon which Nutritious menus are based. The menus are optimally balanced with regard to the best nutrition science available. The most current guidelines are based on information presented in Eat, Drink and Be Healthy, a landmark book written by Dr. Walter Willett. In addition, The China Study offers additional epidemiological research with important implications for health.
Healthy Nutrition Guidelines
Nutritious menus are designed to be optimally healthy. They will strive to meet the following guidelines for health adapted from Walter Willett’s Eat, Drink and Be Healthy as well as providing vegetarian fare. The guidelines are prioritized in order of importance. For example, it would be better to have a little variance in carbohydrates than excessive calories or bad fats.
1) Calorie control:
Since each menu is a dinner or main meal menu, energy will range from 700 to 900 calories, about 1/3 to 1/2 an average person’s daily requirement. It is very important to pay attention to the designated portion sizes.
2) Unsaturated Fats
Saturated, hydrogenated and partially hudrogenated fats will be avoided whenever possible. Fats used in cooking and added to recipes will be primarily unsaturated. Mono- unsaturated oils — canola and olive — will be favored. Nuts and seeds will be used regularly. Fish will be included as a source of omega-3 fatty acids. Overall concern will focus more on the type of fat used than on the quantity.
3) Healthy carbohydrates
Vegetables and fruits will be included liberally. Legumes, including dried beans, lentils, split peas and peanuts will be chosen for both their healthy carbohydrate as well as their healthy proteins. Whole grain foods, including brown rice, whole wheat flour and pasta, rolled oats and other whole grains such as quinoa, millet, barley, etc., will be favored over refined grains. When sugars are used, they will be added as sparingly as possible.
4) Healthy sources and quantity of protein
Protein sources will be primarily plant foods such as legumes, nuts and seeds as well as fish. Infrequently, small amounts of cheese and other dairy foods will be used. Eggs will be used reasonably. The overall quantity of protein will be in the 20 to 30 gram range, about 1/3 to 1/2 an average person’s daily requirement.
Eat, Drink and Be Healthy
Eat, Drink and Be Healthy reflects the latest scientific research available as analyzed by Walter C. Willett, M.D., Dr. P.H., Harvard School of Public Health. Dr. Willett has spent years in research and public education. In his recently published book, he aims “to offer straightforward, no-nonsense advice on nutrition, based on the best information available.” When Walter Willett speaks, it is worth listening. I recommend his book to your reading.
I have summarized Dr. Willett’s conclusions below. The following seven guidelines are his healthiest nutritional strategy to date.
1) Maintaining a stable, healthy weight
“The number that stares up at you from the bathroom scale is the most important measure of your future health.” Control your weight: the lower and more stable your weight, the better your chances of preventing disease. Low Glycemic Index ** diets rather than lowfat diets are the best route to weight loss. Exercise, more than merely a weight control measure, is essential to health. “Too many calories, regardless of food source, are far more important to the development of breast cancer than dietary fat.” “The lowfat, high-carbohydrate diet recommended by the…USDA Food Guide Pyramid may be among the worst eating strategies for someone who is overweight and not physically active.”
2) Replacing saturated and trans fats with unsaturated fats
Eat MORE good fats: unsaturated fats such as canola oil, olive oil, nuts, seeds and fish. Stay away from bad fats: saturated fats such as animal and dairy fats and hydrogenated and partially hydrogenated fats. “It is perfectly fine to get more than 30% of daily calories from fats as long as most of those fats are unsaturated” …AND total calories are controlled. “If you balance the number of calories you eat with the number of calories you burn,…you won’t gain weight on a diet that has 35 or even 40 percent of calories from fat.” “The fat in your diet doesn’t necessarily make you fat …IF you keep your calories constant.”
3) Substituting whole-grain carbohydrates for refined-grain carbohydrates
Eat fewer refined-grain carbohydrates and more whole-grain carbohydrates. Select whole grain carbohydrates such as whole grain breads, brown rice, oats, other whole grains or beans. Potatoes should be an occasional food, consumed in modest amounts. Eating lots of carbohydrates that are quickly digested and absorbed — white flour, white rice, potatoes, sugars, — increases levels of blood sugar and insulin, raises levels of triglycerides and lowers levels of HDL cholesterol…leading to cardiovascular disease and diabetes. “A constant and heavy demand on the pancreas to make insulin appears to be a key ingredient for adult-onset diabetes, especially when paired with lack of exercise.” “Carbohydrates from whole grains, fruits and vegetables should indeed give you the bulk of your calories.” No longer is “simple” and “complex” carbohydrate an adequate distinction; the Glycemic Index:** which shows the effect of various carbohydrates on blood sugar levels, should be used to sort “good” from “bad” carbohydrates. “High levels of blood sugar and insulin surges are now implicated as part of the perilous pathway to heart disease and diabetes.”
4) Choosing healthier sources of proteins by trading red meat for nuts, beans, chicken and fish
You need a minimum amount of protein every day; but don’t overdo it. Too much protein can draw calcium out of the bones and lead to kidney disease. Choose healthy sources of protein. Plant proteins have advantages over animal sources. “The best sources of protein are beans, nuts, fish, poultry and eggs.” Don’t go overboard on soy.
5) Eating plenty of vegetables and fruits
…but hold the potatoes. A diet rich in fruits and vegetables protects against heart disease, a variety of cancers, development of cataracts and macular degeneration. Aim for a minimum of 5 servings a day; 7 to 9 servings would be better
6) Using alcohol in moderation
“Alcohol, in moderation, is probably good for most people.” Moderation means one drink a day for women; one or two for men. Any alcohol-containing beverage — wines, beer, hard liquor –offers the same benefits. “People who have one or two alcoholic drinks a day are less likely to have a heart attack or die from heart disease than nondrinkers or heavy drinkers.” “For women, 2 drinks a day increase the chances of developing breast cancer by 20 to 25 percent.” Folic acid may help to reduce this.
Adequate fluid is important. Water is the best way to get the most important nutrient, water. Regarding milk: “there are more reasons not to drink milk in large amounts than there are to drink it. I don’t recommend it as a beverage for adults.” “Coffee is a remarkably safe beverage.” Tea also has some benefits.
7) Taking a daily multivitamin for insurance
Supplement the hard-to-get-enough-of nutrients. There is not a calcium emergency. “Too much calcium might be a bad thing.” Elevated intakes of calcium do not prevent broken bones in old age. Eating a lot of dairy products may increase ovarian and prostate cancers.
** The Glycemic Index measures how a particular carbohydrate food affects the blood sugar level. In general, refined sugar, potato, rice, and bread have a greater effect on blood sugar and, therefore, insulin production, than legumes, fruit, most vegetables and pasta.
Some of you may already be doing all of the above. Congratulations. Most of us, however, continue to strive toward optimal health. It is important to remember that the guidelines are listed in order of importance. Work on the first ones first. And don’t try to do it all at once. You have a lifetime to perfect this, hopefully a long, healthy lifetime.
There are about 40 nutrients, substances that the human body needs to consume on a regular basis to survive. The most important nutrient is water. More than half of our body is water. It makes sense, therefore, that daily replenishment of this essential component is vital for health. Energy-yielding nutrients needed in large amounts — protein, fat and carbohydrate — are called macronutrients. The percentage of total daily Calories supplied by each of these is a major determinant of health. The remaining nutrients — vitamins and minerals — are needed in small, in some cases minuscule, amounts. We call these micronutrients. Fiber, the remaining essential substance, is not a true nutrient as it does not actually enter the bloodstream, passing through the body via the gastrointestinal tract.
The body requires a fairly precise amount of protein daily: that which is needed to maintain and repair bodily tissues and to provide growth for infants, youth and pregnant women. This amount depends on body size, averaging about 53 grams of protein per day for a woman and about 63 grams for males. This level of protein intake represents about 10% of daily Calories. Protein amounts eaten beyond requirements are burned as energy or stored as fat.
Protein is available from both animal and plant foods. It used to be thought that animal protein was superior to plant protein. The truth, however, is that with a varied and balanced diet, complete protein can be obtained from plant sources alone. Nutrition science verifies that plant protein is actually healthier than animal protein. As animal protein amounts increase in the diet, “diseases of nutritional extravagance” such as heart disease and many cancers also increase. Plant protein, unlike animal protein, tends to be protective and preventive of such diseases. As excess protein is consumed, urea nitrogen levels rise in the blood; along with their rise, the rates of degenerative diseases also increase.
Fats are the current darling of the food police. This is not without some justification, of course, but it is wise to distinguish the various kinds of fats and keep the overall balance of the entire diet in mind when thinking “nutrition and health.” It is confusing to recognize that fat is a nutrient, an essential food substance, and yet to understand how much of which type or types of fat we really need to eat.
Fats are either saturated or unsaturated, a chemical distinction referring to stability. Saturates are stable; unsaturates are unstable. Simple, so far. Foods with fat all contain a mix of saturates and unsaturates, yet we consider them one or the other depending on which type predominates. For example, examples of saturated fats include butter, margarine, vegetable shortening, lard and palm and coconut oils. Unsaturates sort into two piles, depending on whether they are primarily monounsaturated or polyunsaturated. Monounsaturates include olive oil, canola oil and various nut oils. Polyunsaturates include soy oil, cottonseed oil, safflower oil, corn oil and fish oil. Fats that started out unsaturated can be saturated through a process of hydrogenation. Hydrogenation or partial hydrogenation creates substances called trans fatty acids which are unhealthful. Hydrogenated fats are found in margarines and vegetabled shortenings and foods made with these products, including most commercially baked goods.
As a nutrient, we need only a small amount — less than one teaspoonful — of a particular polyunsaturated fat. It has been suggested that we also require another form of polyunsaturated fat called “omega-3 fatty acids.” These particular fats are found in fish oils, flax seed and, in small amounts, in canola oil, soy oil and walnut oil. Omega-3s prevent heart arrthmias and sudden cardiac death, a cause of half of all heart disease deaths. The American Heart Association recommends eating at least 2 servings of seafood weekly.
We have no need for saturates. Since their consumption is related to elevations in serum cholesterol levels, it is prudent to avoid saturates — as well as trans fats from hydrogenation — whenever possible.
Since more than 80% of the oil used commercially is soy oil, we probably get more polyunsaturates than we need for a healthy fatty acid balance. It makes sense, therefore, to use monounsaturates at home.
Since we get a sense of completion of a meal or sense of satiety from fat, we all enjoy eating more than a paltry teaspoonful across an entire day. We also like the flavors carried by fats and the mouth feel. And, let’s face it, some of our favorite foods are just plain fat — think cheese, chocolate, I could go on. How much fat is too much?
Even after fine tuning our diet to maximize the good fats and minimize the bad, we still need to pay attention to the overall intake. Fats are very calorie-dense. As long as our caloric intake is managed to maintain healthy weight, we can include good fats necessary for palatability and to insure that we eat the necessary vegetables, legumes and other nutrient-dense foods that often accompany them.
All carbohydrates ultimately convert to glucose in the body. We consume them as complex carbohydrates: starches, or simple carbohydrates: sugars. The nutritional difference is that starchy foods provide other nutrients such as vitamins and minerals and are rich sources of dietary fiber. Sugars, except for those in fruits, are usually empty calories, devoid of extra dietary goodies. They digest more rapidly, assaulting blood sugar levels and associated insulin responses.
Only plant foods supply carbohydrates, with the exception of lactose, a sugar in milk. And, since most of our calories need to come from carbohydrate (there are no other sources after protein and fat except for alcohol), we are looking at a vegetarian reality. Look on the bright side. Only unrefined plant foods have fibers, those necessary cholesterol lowerers and stool softeners. There is no cholesterol in any plant food; only animal foods have cholesterol. And, only plant foods bring anti-oxidants into the diet. These are only some of the reasons that “Five-A-Day,” the campaign to increase fruit and vegetable consumption, is so important for our health.
Vitamins and Minerals:
If one consumes a balanced diet as described above — appropriate protein, primarily from plant foods; good fats, primarily monounsaturated and omega-3; and whole grains, legumes, and adequate vegetables and fruits — AND one has not restricted energy intake for extreme weight loss AND one eats a variety of different foods, it is almost impossible not to obtain adequate micronutrients.
A vitamin B12 deficiency is possible with a very strict vegan diet. Other possible nutrients of concern include vitamins B6, folic acid and E and minerals iron, magnesium and zinc. Foods such as legumes, whole grains, dark leafy greens, nuts and seeds are good sources of these micronutrients and make a major contribution to a healthy diet. Supplements should be used to fill in the gaps if the diet is not providing enough of these hard-to-get-enough-of nutrients. They should not be utilized as a substitute for a healthy diet. The Recommended Dietary Allowances (RDA) offer general guidelines for safe supplement intakes.
Dietary fiber is found only in plant foods. There are two general types of fibers, soluble and insoluble. The soluble fibers aid the body in lowering levels of serum cholesterol. These fibers are found in legumes, oat bran, the white, pithy part of citrus peel and unripe fruits. Insoluble fibers are prevalent in wheat bran and most vegetables. They act primarily in the large intestine, helping to prevent diverticulosis and regulate bowel movement.
Although nutrition science is a growing body of research, there is still much to learn about the relationships between foods and health and disease prevention.
This ongoing nutrition research project is the most comprehensive and most compelling study ever undertaken on the relationships between what we eat and the risks of developing the chronic degenerative diseases so prevalent in our culture. Once aware of this study, it is hard to ignore its implications.
As a percentage of total calories, the Chinese average 10% from protein, 15% from fat and the remainder primarily from carbohydrate. (A small percentage derives from alcohol, the only other energy source.) Based on this data and adjusting the fat toward a more attainable goal, an optimal daily dietary balance of calories might be 10% from protein, 20% from fat, and 70% from carbohydrate.
The Chinese Diet:
The average consumption of fat in China is 15% of total calories, less than half that of the West. Their protein intake is about two-thirds that of the West, but only 10% is animal-based whereas 70% of the Western protein intake comes from animal foods. Depending upon the region of China, the diet may be based on rice, wheat, corn, millet, sweet potatoes or other starches; they consume far more vegetables than Westerners.
Dietary Guidelines Suggested by the Study:
- Use little or no added fats or oils
- Eliminate or cut down on animal proteins of all types
- Eat a generous amount of plant-based foods
- Be cautious regarding supplements; they do not substitute for real foods
Begun in 1983, the China Project is a collaborative effort primarily between nutrition scientists in America and China. The chief investigator is Dr. T. Colin Campbell, a professor of nutrition and biochemistry who holds an endowed chair at Cornell University. Dr. Chen Junshi of the Chinese Academy of Preventive Medicine in Beijing works with Dr. Campbell. Scientists from Oxford, England, and laboratories throughout the world have also collaborated on the study.
China was chosen as the site of the study as it offers a living laboratory unlike anywhere else in the world. The genetically similar Chinese tend to spend their entire lives in the same area, eating the same kinds of locally grown foods throughout their lives. Their diets as well as their disease rates vary considerably from one region to another. Because of the immensity of the country, both “diseases of poverty” such as pneumonia, tuberculosis and rheumatic heart disease and “diseases of affluence” such as diabetes, cancer and coronary heart disease are found. The scientists wanted to find out if the varying diets in different parts of China would correlate to varying death rates from certain diseases.
Researchers collected data on how people live and die in 65 counties throughout China. Some of the data gathering required days of travel across rough terrain in order to reach nomads on the Soviet border or villagers in an oasis near the Gobi desert. In the 1989 survey, more than 1000 items of information were collected on each of the 10,200 Chinese and Taiwanese adults that were observed, interviewed, measured and poked for several days. Every piece of food they ate was noted; urine and blood samples were taken.
Truly, this is the most comprehensive epidemiological study ever undertaken on the relationships of diet and disease. It is unique in that it looks at the effect of overall diet and lifestyle on health, not just a single food or food component relative to a single disease.
A high blood level of cholesterol was consistently associated with many cancers, including leukemia, liver, colon, rectum, lung and brain. The women in the villages that had the highest cholesterol levels also had the highest levels of cancers, heart disease and diabetes, while the women with the lowest cholesterol levels had the lowest levels of these diseases. It is important to note that the highest cholesterol levels in rural China were near the lowest levels found in the U.S. In the U.S., cholesterol levels average 210 – 220 mg/dl. The rural Chinese average 125 – 130 mg/dl. The Chinese who had even lower levels suffered significantly less cancer and heart disease than their more “average” compatriots.
Animal protein and saturated fat cause cholesterol levels to rise. Metabolic studies in humans show that animal protein raises blood cholesterol more than does saturated fat. In effect, lean meats may be just as damaging to your cholesterol levels as fatty bacon.
In any group of men, seventeen times more American men will die of heart disease than Chinese men. Dr. Richard Peto of Oxford University, a major researcher on the project, says, “The Chinese experience shows that most Western coronary heart disease is unnecessary.”
Urea nitrogen, leftover after protein metabolizes in the body, is directly related to chronic degenerative disease rates. As excess protein is consumed, urea nitrogen levels rise in the blood; as urea nitrogen levels rise, so do diseases of affluence. Not surprisingly, data gathered near the more affluent cities of Beijing and Shanghai where diets are richer with animal products showed higher rates of degenerative diseases associated with affluence. Even small intakes of animal foods, such as meat, eggs and milk, are associated with significant increases of cancer, heart disease and diabetes. Conversely, the higher the percentage of plant foods in the diet, the less the chance of getting these diseases.
The Chinese have a low rate of osteoporosis: they have only about one fifth the number of hip fractures as in the West. They consume little if any dairy and ingest low amounts of calcium. A different level of physical activity might explain some of the difference. But, they also eat far less protein than Westerners. High protein intakes, especially animal proteins, cause calcium to be excreted in the urine. A person eating 142 grams of protein a day will excrete twice as much calcium as a person eating 47 grams, the amount required by an average woman. If more calcium is excreted than is eaten, the deficit is made up by withdrawing calcium from the bones, weakening them over time.
In China, 30% more calories per kilogram of body weight are consumed than in the U.S. Despite averaging 270 more calories per day, the average Chinese is thinner than the average American. Could the source of the calories make a difference? The Chinese eat 6 – 24% of their calories as fat; Americans consume about 30-46% of calories as fat.
Antioxidants may help protect against cancers. The study found that the lower the intakes of vitamin C and beta carotene, two antioxidants, the higher the rate of esophageal and stomach cancers. Antioxidants are only found in plant foods; they are not in animal foods.
Most of the iron in the Chinese diet comes from plant foods. While it is true that the iron in vegetables and grains is less easily absorbed than heme iron which is found in animal foods, the Chinese had normal blood levels of iron. The added fiber in a plant-rich diet did not appear to interfere with bioavailability of iron.
In China, high levels of breast cancer were associated with several things: high intake of dietary fat; high blood levels of cholesterol, estrogen and testosterone; and early age at first menstruation. We know that dietary fat and blood cholesterol are related to diet. Estrogen and other reproductive hormones increase in the blood as meat, milk and fat increase in the diet. Testosterone also was high in those women who ate more fat and animal foods. Even menarche is diet related: diets high in fat, calories and animal protein lower the age of menarche by accelerating growth. The earlier the onset of menstruation the greater the likelihood of developing cervical as well as breast cancer.
Lung cancer rates reflect the introduction and promotion of cigarettes in China. It is estimated that around 50 million of the existing Chinese population will die prematurely of lung diseases.
The relationship of dietary fiber and colon cancer in the Chinese population reflects that the higher the intake of a wide variety of fibers, the lower the rate of colon cancer. The Chinese eat three times as much fiber as Americans. Fiber is only found in plant foods.
People infected with chronic viral hepatitis (type B and C) — about 12-13% of the Chinese population — were more likely to get liver cancer. Among those people, the ones with the highest cholesterols levels were most likely to develop liver cancer.
People who have stomach ulcers or chronic stomach infections from Helicobacter pylori bacteria are more likely to get stomach cancer. In the absence of refrigeration, foods are preserved by salting and fermentation, possibly contributing to this problem. Even in people predisposed to liver and stomach cancers, a higher intake of plant foods led to fewer cases.
Carcinogenesis, the development of cancer, appears to be turned on by animal protein and turned off by plant protein, even if cancer has already been initiated. It appears that once the body has met its protein needs (about 8 – 10% of the daily calories), the excess protein begins to feed precancerous lesions and tumors.
Researchers found that the higher the levels of copper in the blood, the higher the rate of certain cancers.
There was a strong but unexplained association between cadmium in the urine and primary liver cancer.
There was an intriguing correlation relationship between herpes simplex infections and heart disease.
The shorter Chinese stature was more likely related to early childhood infections that to lack of protein or nutrients.
Chinese women report fewer difficulties with symptoms of menopause. This may be related to overall lower estrogen levels in Chinese women, higher intakes of magnesium and vitamin B6 which appear to reduce symptoms of PMS, or higher intakes of phytoestrogens such as genistein in soy foods which counter falling estrogen levels at menopause.
Chinese men have the lowest advanced prostate cancer rates in the world: one in every 100,000 men, while Chinese-American men living in San Francisco have a rate 19 times higher. High levels of testosterone trigger rapid growth of prostate cancer cells. Testosterone production is accelerated by an animal protein diet, while a diet low in fat and high in fiber slows its production and speeds its elimination. Furthermore, vegetables contain plant estrogens that can help normalize the proportion of testosterone to estrogen in the body. Several studies have shown that men eating diets high in phytoestrogen containing foods, such as soybeans and peas, are less likely to develop prostate cancer.
Begin to shift toward a vegetarian diet, one that is increasingly plant oriented and decreasingly animal. Each step in that direction is a step toward health and away from disease.
The American Dietetic Association notes that a lowfat, meatless diet reduces obesity, coronary heart disease, high blood pressure, diabetes, osteoporosis, kidney stones, gallstones and cancers of the colon, breast and lung.
Dean Ornish, M.D., concurs. “We have to go beyond the [U.S. Dietary] Guidelines to a lowfat, vegetarian diet. Animal products…are the main culprit in what is killing us. We can absolutely live better lives without them.”
Neal Barnard, M.D., Director of the Physicians Committee for Responsible Medicine, informs us that two-thirds of Americans alive today will die of cancer or heart disease, most of it diet-related and, therefore, preventable.
Today we have the opportunity to live the most disease-free lives in history. The China Study provides us with guidance on how to accomplish that. Will we take the steps necessary to turn this knowledge into action?
Reference: The China Project: Keys to Better Health Discovered in Our Living Laboratory by T. Colin Campbell, Ph.D. and Christine Cox; 1996, New Century Nutrition, Cornell Technology Park, P O Box 4716, Ithaca NY 14852