We must eat to live. The quality of our lives is partially dependent upon the quality of foods we eat. Food gives us the energy fuel and building materials our bodies need to perform millions of vital physiological functions every day. Macronutrients-proteins, carbohydrates and fats-comprise the greatest portion of the human diet.
We must eat to live. The quality of our lives is partially dependent upon the quality of foods we eat. Food gives us the energy fuel and building materials our bodies need to perform millions of vital physiological functions every day.
Macronutrients proteins, carbohydrates and fats comprise the greatest portion of the human diet. A calorie is the measurement used to determine the energy value of macronutrients. The word calorie is derived from the Latin word "calor" which means heat.
Our ideas and understanding of what constitutes a healthy diet have changed drastically in the last few decades. Expert opinions vary widely regarding the ideal ratio of proteins, carbohydrates and fats we should consume for the most balanced diet.
Meat and dairy protein sources were once considered the only valuble sources of useable protein. We were taught to eat meat at virtually every meal. Now experts are encouraging us to eat more vegetable-source proteins from soy foods, lentils and other legumes.
Carbohydrates used to be thought of as just starches. There was no consideration of the differences between complex and simple carbohydrate sources. Today many people understand the importance of choosing more complex carbohydrates to sustain energy levels and increase fiber intake.
The way we view fats has undergone the most radical change of all. We have moved beyond grouping all fats into one category, and have begun to understand the role of essential fatty acids and to distinguish between the beneficial sources of fat and the unhealthy sources.
Protein is composed of carbon, hydrogen, oxygen and nitrogen and is responsible for building and repairing body tissue. After water, protein is the most plentiful substance in our bodies. It constitutes about one-fifth of our body weight and is the major constituent of every living cell and body fluid except bile and urine.
A continuous supply of protein is needed for cell building and regeneration, but eating more animal-source proteins than the body requires taxes the kidneys and can contribute to obesity.
Proteins are classified nutritionally as being complete or incomplete. Complete proteins, such as eggs, are capable of promoting growth and health. Partially complete proteins are capable of maintaining life but lack the full complement of amino acids to promote growth. The combination, however, of two incomplete protein sources such as beans and whole grains, combine to form a complete protein with all of the essential amino acids.
Protein molecules are composed of amino acids linked together in a structural chain. The configuration of these structures can be in the form of helixes, spheres or branched structures, depending upon the number, variety and order of the amino acids.
There are twenty-two amino acids required to build protein, eight of which are classified as essential and two (arginine and histidine) which are considered semie ssential. The essential amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine; these must be provided through dietary sources. The remaining ten amino acids are classified as nonessential and are manufactured within the body. They include alanine, aspartic acid, cysteine, cystine, glutamine acid, glycine, proline, lysine, serine and tyrosine.
The most common food sources of protein are meat, fish, fowl, seafood, eggs, dairy products, whole grains and legumes (beans, peas, tofu and tempeh). The caloric content of a gram of protein is four calories.
More and more people are choosing to either eliminate or reduce their consumption of meat and dairy products for health or ethical reasons. In this case, it is important to consume more vegetable-source proteins and learn the simple rules of protein combining to ensure all of the amino acids are present in the diet.
Many people who reduce their meat intake make the mistake of increasing their cheese consumption and run the risk of eating too much fat. This error can be avoided by including more tofu, legumes and whole grains in the daily diet.
PDF Table of Vegetarian Protein Sources (part 2)
Formed by green plants as a product of photosynthesis, carbohydrates are the most abundant compounds on earth. The primary dietary carbohydrates consist of starch, sugar and fiber.
Starches, or complex carbohydrates, include vegetables, fruits, legumes and grains. Simple carbohydrates, or sugars, include table sugar, honey, natural fruit sugars and molasses. Fiber includes cellulose, hemicellulose and pectin as found in whole grains, legumes, fruits and vegetables.
Carbohydrates are the main and preferred source of energy for all bodily functions, sparing protein for use in building and repairing tissue. Carboyhdrates are also important in the normal metabolism of fat, and the digestion and absorption of other foods. They are also beneficial in forming mucopolysaccharides and other body lubricants.
After being broken down into glucose, a simple sugar, excess carbohydrates not immediately required for energy, are stored as glycogen in the muscles or liver. The stored muscle glycogen can then be readily used by the muscles, while the glycogen stored in the liver can be released as glucose (blood sugar) and transported by the bloodstream. If these two storage areas are full and there is no need by the body for more carbohydrates, excess glucose is converted by the liver into body fat by a metabolic process called lipogenesis.
There is less of a tendency to overeat when complex carbohydrates make up the bulk of carbohydrate intake. Complex carbs are more filling due to the more sophisticated nature of their molecular structure. Their high fiber content gives a greater sense of fullness more quickly than simple carbohydrates.
Eating too many simple carbohydrates may cause dental decay, obesity and nutritional deficiencies. A lack of carbohydrates could result in energy loss, ketosis, depression, nutritional deficiencies and loss of essential body protein.
The fiber component of carbohydrates helps to regulate bowel function. Due to the laxative and cleansing effect fiber has on the colon, a high fiber diet has been shown to reduce the rate of colon and rectal cancers. A significant increase in dietary fiber may cause temporary intestinal distress such as bloating, flatulence or diarrhea. These symptoms will subside as the digestive system adjusts to the increased fiber. A digestive enzyme supplement containing cellulase, the enzyme needed to digest fiber, will offer relief for the temporary symptoms and will encourage the body's own enzyme production. One gram of carbohydrate has four calories.
Essential Fatty Acids (Healing Fats)
Fats and oils are made up of building blocks called fatty acids. They are either saturated, monounsaturated or polyunsaturated. Although some fats are implicated in increasing our chances of developing heart disease and cancer, others are essential, meaning we have to eat them to survive, and they are needed for special functions in the body besides energy. One gram of fat has nine calories.
Fats that we cannot make ourselves are called essential fatty acids (EFAs). There are two main fats that are classified as essential: linoleic acid (LA or omega-6 polyunsaturated fatty acid) and alpha-linolenic acid (LNA or omega-3 superunsaturated fatty acid). From these, our body makes several derviatives, including GLA, DGLA and AA from the omega-6 LA; and EPA and DHA from the omega-3 LNA. In addition, our body makes hormone-like prostaglandins (sometimes called "super hormones") from essential fatty acids. All of these essential fatty acid derviatives are extremely important for good health.
Essential fatty acids and their derivatives are essential for circulation, hemoglobin production, membrane (skin) function, recovery from fatigue, prostaglandin (hormone) synthesis, growth, cell division, brain development, immune function and anti-inflammatory responses. They are also necessary for energy production, brain function, healing, learning, athletic performance, beauty and weight loss.
If we do not get enough of these kinds of fats, if they are not consumed in the proper proportion, or if we do not get enough of other essential nutrients that assist in their metabolism, deficiency symptoms will eventually appear.
Many degenerative diseases, such as heart disease, cancer and arthritis are due to a deficiency of one or both of these types of essential fatty acids.
Alpha-linolenic acid lowers triglycerides and protects the "good" cholesterol. Good cholesterol is the high density lipoproteins (HDL) that carry cholesterol out of the body. "Bad" cholesterol is the low density lipoproteins (LDL) which adhere to the artery walls. LNA retards the formation of blood clots in the arteries, helps to control blood pressure and has been shown to have an antitumor role.
Deficiency of essential fatty acids can also cause skin problems, behavior changes, liver and kidney problems, sterility, miscarriage, poor healing of wounds, arthritis-like symptoms, heartbeat abnormalities, dry eyes, gland problems, weakness, clumsiness, learning and visual problems, water retention, growth retardation and problems in every cell, tissue and organ in the body.
Omega-6 essential fatty acids are found in oils. Omega-3 is abundant only in flax seed and some fish oils. We have doubled our intake of omega-6 but decreased omega-3 to one-sixth of what we used to get in traditional diets.
The balance of omega-6 to omega-3 is very important. If we get too much of one, we become deficient in the other. Most oils are poorly balanced. Flax has too little omega-6. Most other oils (sunflower, sesame) have no omega-3, or too little (soy bean). As a result, we have to mix and match essential fatty acids, or use blends. The therapeutic blends are richest in alpha-linolenic and this is the one that increases energy, improves learning, has antitumor effects, prevents heart attacks, strokes and embolisms, lowers high blood pressure, and helps with weight loss.
Saturated fats are usually solid at room temperature. The only sources of naturally saturated fats in our diets are animal fats and tropical oils. Animal fats include red meat, pork, dairy fats, butter and cheese. Tropical oils are from plant sources and include coconut, palm, palm kernel and cocoa butter.
In saturated fats, the fat molecule is saturated with hydrogen atoms, leaving no more empty spaces for additional hydrogen molecules to attach.
PDF Table of Animal Fats, Vegetarian Fats and Fats & Oils
Unsaturated fats include most vegetable oils and are usually liquid at room temperature. The fat molecules in unsaturated fats have empty spaces where more hydrogen molecules can attach, leaving unsaturated fats more susceptible to molecular damage and rancidity. Proper extraction and storage of vegetable oils is an integral part of preventing this damage
Polyunsaturated and Superunsaturated Fats
Polyunsaturated fats are found in most foods. Omega-3 superunsaturated fats are found primarily in cold water fish and flax seed, and omega-6 polyunsaturated fats are found in nuts, oils from nuts, seeds and beans. These fats are liquid at room temperature. The word "poly" means "many," hence, polyunsaturated fats have many spaces not taken up by hydrogen molecules and double bonds
Mono means "one," so monounsaturated fats have just one bond and two empty spaces not taken up by hydrogen molecules. Mono-unsaturated fats are found in most foods, but mainly in vegetable and nut oils such as almond, olive, peanut and canola. These fats are also liquid at room temperature
Hydrogenated Fats and Trans-Fatty Acids
The process of hydrogenation is extremely damaging to oils and poses the most dangerous health risks. Hydrogenation is a denaturing process that makes liquid vegetable oils hard. Vegetable margarine and shortening are hydrogenated fats. All hydrogenated fats become artificially saturated (hard).
Hydrogenated fats are most often found as ingredients in commercially-prepared baked goods, candies, ice cream, chocolate, snack foods and potato chips.
Structural damage to the oil is created by hydrogenation. The naturally occuring cis structure of the fat is converted to a trans structure, creating trans-fatty acids. Trans-fatty acids have recently been proven to be one of the key health risks associated with heart disease and cancer.
Many researchers have implicated hydrogenated fats with heart disease, cancer, diabetes and obesity, as well as undesirable effects on immune function, reproduction and lactation. Hydrogenated fats serve no function in the body. In fact they interfere with the metabolism of essential fatty acids, normal growth and development, the immune system and anti-inflammatory responses. Trans fats increase the "bad" cholesterol, decrease the "good," and increase blood triglycerides, all risk factors for heart disease.
Eicosapentanoic acid (EPA), found in fish oils, is a fatty acid which has the same health benefits as the omega-3 essential fatty acid alpha-linolenic acid. EPA is an intermediary step in the body's conversion of alpha-linolenic acid to series-3 prostaglandins.
Since the conversion of linolenic acid to EPA is susceptible to blockage by vitamin or mineral deficiencies, stress and alcohol, eating cold-water fish can be a very useful way of getting the substance needed to make series-3 prostaglandins.
Processed fats are refined and subjected to many chemical changes. Various raw oils and animal fats like lard and beef fat are bleached, deodorized, filtered, aromatized, hardened, emulsified and eventually treated with insecticides.
Margarine, shortening and refined oils are made from hydrogenated vegetable oils, a process which turns the fat into a solid form and destroys the natural vitamins. These sticky and difficult-to-dissolve fats are a major contributor to heart disease, skin problems, PMS and prostate problems. Margarine and shortening consist of up to sixty percent trans-fatty acids and contain other toxic chemicals, as well as aluminum and nickel residues from the hydrogenation process.
Avoid all hydrogenated fats! The corporate food industry takes advantage of the fact that food tastes better with fat, and "hides" large quantities of unhealthy hydrogenated fats in many processed foods. So-called "all-purpose" vegetable oils are usually made from cottonseed oil which comes from plants heavily treated with pesticides.
The best way to avoid hydrogenated fats is to read labels and check all the ingredients of packaged foods. Buy foods as fresh and unprocessed as possible and prepare them yourself to maintain control over what you eat and to avoid hidden unhealthy fats.
Foods in which Polyunsaturated Fats are the Main Type of Fat
Foods in which Trans-fatty acids are high
|© Mary Enig, Ph.D., F.A.C.N., C.N.S. 1993 technical report on the trans fatty acids|
Foods in which Saturated Fat Is the Main Type of Fat
Foods in which Monounsaturated Fat Is the Main Type of Fat
The Cholesterol Controversy
Cholesterol is perhaps the most talked about and the most misunderstood fat. We manufacture our own cholesterol from saturated fats, other fats and sugars.
We need cholesterol to produce hormones, vitamin D and bile acids. It is a necessary part of our cell membranes and our brains.
Even if we did not eat cholesterol, we would still make it. Blood cholesterol is different from dietary cholesterol. Only animal-derived foods contain cholesterol, plant derived foods are cholesterol-free.
The consumption of beef fat and other fats with trans-fatty acids tax the liver and contributes to clogged arteries. Blood cholesterol levels can be controlled through dietary measures.
Soluble fiber intake increases the body's removal of cholesterol. Fiber is only found in plant foods; animal-derived foods are fiber free. A strict vegetarian diet can significantly reduce high-cholesterol levels within a month.
While the average meat eater will have a forty to fifty percent chance of developing heart disease, for strict vegetarians, the risk is minimal. Strict vegetarians avoid all animal-derived foods (meat, eggs, dairy, fish), but have increased vitamin and mineral intake from fruits, vegetables, grains and legumes. This also means they naturally consume more foods that provide antioxidants and fiber.