nutrition
Strategy adopted by an organism to obtain the chemicals it needs to live, grow, and reproduce. These chemicals are nutrients that are absorbed from the environment, such as mineral salts, or chemicals made inside the body of a plant or animal. Nutrition is a term also used to describe the science of food, and its effect on human and animal life, health, and disease. Nutrition involves the study of the basic nutrients required to sustain life, their bioavailability in foods and overall diet, and the effects upon them of cooking and storage. It is also concerned with dietary deficiency diseases.
Plant nutrition is very different from animal nutrition in several ways. In a plant high-energy food (for example, carbohydrate) is made inside the plant by photosynthesis. An animal obtains high-energy food by eating a plant or another animal. Nutrients from the environment are absorbed by different parts of plant and animal bodies. In a plant, nutrients are absorbed from soil water by the roots (see root hair cell). In an animal, nutrients are absorbed from the gut by the epithelium cells lining it.
There are six classes of nutrients: water, carbohydrates, proteins, fats, vitamins, and minerals.
WaterWater is involved in nearly every body process. Animals and humans will succumb to water deprivation sooner than to starvation.
CarbohydratesCarbohydrates are composed of carbon, hydrogen, and oxygen. The major groups are starches, sugars, and cellulose and related material (or ‘roughage’). The prime function of the carbohydrates is to provide energy for the body; they also serve as efficient sources of glucose, which the body requires for brain functioning, utilization of foods, and maintenance of body temperature. Roughage includes the stiff structural materials of vegetables, fruits, and cereal products.
ProteinsProteins are made up of smaller units, amino acids. The primary function of dietary protein is to provide the amino acids required for growth and maintenance of body tissues. Both vegetable and animal foods are protein sources.
FatsFats serve as concentrated sources of energy, and protect vital organs such as the kidneys and skeleton. Saturated fats derive primarily from animal sources, unsaturated fats from vegetable sources such as nuts and seeds.
VitaminsVitamins are essential for normal growth, and are either fat-soluble or water-soluble. Fat-soluble vitamins include A, essential to the maintenance of mucous membranes, particularly the conjunctiva of the eyes; D, important to the absorption of calcium; E, an anti-oxidant; and K, which aids blood clotting. Water-soluble vitamins are the B complex, essential to metabolic reactions, and C, for maintaining connective tissue.
MineralsMinerals are vital to normal development; calcium and iron are particularly important as they are required in relatively large amounts. Minerals required by the body in trace amounts include chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc.
Recommended daily allowances (RDAs) have been established for these nutrients to give a balanced diet.
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NUTRIMENT
Nutrition
Definition
Good nutrition can help prevent disease and promote health. There are six categories of nutrients that the body needs to acquire from food: protein, carbohydrates, fat, fibers, vitamins and minerals, and water.
Proteins
Protein supplies amino acids to build and maintain healthy body tissue. There are 20 amino acids considered essential because the body must have all of them in the right amounts to function properly. Twelve of these are manufactured in the body but the other eight amino acids must be provided by the diet. Foods from animal sources such as milk or eggs often contain all these essential amino acids while a variety of plant products must be taken together to provide all these necessary protein components.
Fat
Fat supplies energy and transports nutrients. There are two families of fatty acids considered essential for the body: the omega-3 and omega-6 fatty acids. Essential fatty acids are required by the body to function normally. They can be obtained from canola oil, flaxseed oil, cold-water fish, or fish oil, all of which contain omega-3 fatty acids, and primrose or black currant seed oil, which contains omega-6 fatty acids. The American diet often contains an excess of omega-6 fatty acids and insufficient amounts of omega-3 fats. Increased consumption of omega-3 oils is recommended to help reduce risk of cardiovascular diseases and cancer and alleviate symptoms of rheumatoid arthritis, premenstrual syndrome, dermatitis, and inflammatory bowel disease.
Carbohydrates
Carbohydrates are the body's main source of energy and should be the major part of total daily intake. There are two types of carbohydrates: simple carbohydrates (such as sugar or honey) or complex carbohydrates (such as grains, beans, peas, or potatoes). Complex carbohydrates are preferred because these foods are more nutritious yet have fewer calories per gram compared to fat and cause fewer problems with overeating than fat or sugar. Complex carbohydrates also are preferred over simple carbohydrates by diabetics because they allow better blood glucose control.
Fiber
Fiber is the material that gives plants texture and support. Although it is primarily made up of carbohydrates, it does not have a lot of calories and is usually not broken down by the body for energy. Dietary fiber is found in plant foods such as fruits, vegetables, legumes, nuts, and whole grains.
There are two types of fiber: soluble and insoluble. Insoluble fiber, as the name implies, does not dissolve in water because it contains high amount of cellulose. Insoluble fiber can be found in the bran of grains, the pulp of fruit and the skin of vegetables. Soluble fiber is the type of fiber that dissolves in water. It can be found in a variety of fruits and vegetables such as apples, oatmeal and oat bran, rye flour, and dried beans.
Although they share some common characteristics such as being partially digested in the stomach and intestines and have few calories, each type of fiber has its own specific health benefits. Insoluble fiber speeds up the transit of foods through the digestive system and adds bulk to the stools, therefore, it is the type of fiber that helps treat constipation or diarrhea and prevents colon cancer. On the other hand, only soluble fiber can lower blood cholesterol levels. This type of fiber works by attaching itself to the cholesterol so that it can be eliminated from the body. This prevents cholesterol from recirculating and being reabsorbed into the bloodstream. In 2003, the World Health Organization released a new report specifically outlining the link of a healthy diet rich in high-fiber plant foods to preventing cancer.
Vitamins and minerals
Vitamins are organic substances present in food and required by the body in a small amount for regulation of metabolism and maintenance of normal growth and functioning. The most commonly known vitamins are A, B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), B12 (cobalamin), C (ascorbic acid), D, E, and K. The B and C vitamins are watersoluble, excess amounts of which are excreted in the urine. The A, D, E, and K vitamins are fat-soluble and will be stored in the body fat.
Minerals are vital to our existence because they are the building blocks that make up muscles, tissues, and bones. They also are important components of many life-supporting systems, such as hormones, oxygen transport, and enzyme systems.
There are two kinds of minerals: the major (or macro) minerals and the trace minerals. Major minerals are the minerals that the body needs in large amounts. The following minerals are classified as major: calcium, phosphorus, magnesium, sodium, potassium, sulfur, and chloride. They are needed to build muscles, blood, nerve cells, teeth, and bones. They also are essential electrolytes that the body requires to regulate blood volume and acid-base balance.
Unlike the major minerals, trace minerals are needed only in tiny amounts. Even though they can be found in the body in exceedingly small amounts, they are also very important to the human body. These minerals participate in most chemical reactions in the body. They also are needed to manufacture important hormones. The following are classified as trace minerals: iron, zinc, iodine, copper, manganese, fluoride, chromium, selenium, molybdenum, and boron.
Many vitamins (such as vitamins A, C, and E) and minerals (such as zinc, copper, selenium, or manganese) act as antioxidants. They protect the body against the damaging effects of free radicals. They scavenge or mop up these highly reactive radicals and change them into inactive, less harmful compounds. In so doing, these essential nutrients help prevent cancer and many other degenerative diseases, such as premature aging, heart disease, autoimmune diseases, arthritis, cataracts, Alzheimer's disease, and diabetes mellitus.
Water
Water helps to regulate body temperature, transports nutrients to cells, and rids the body of waste materials.
Origins
Unlike plants, human beings cannot manufacture most of the nutrients that they need to function. They must eat plants and/or other animals. Although nutritional therapy came to the forefront of the public's awareness in the late twentieth century, the notion that food affects health is not new. John Harvey Kellogg was an early health-food pioneer and an advocate of a high-fiber diet. An avowed vegetarian, he believed that meat products were particularly detrimental to the colon. In the 1870s, Kellogg founded the Battle Creek Sanitarium, where he developed a diet based on nut and vegetable products.
Purpose
Good nutrition helps individuals achieve general health and well-being. In addition, dietary modifications might be prescribed for a variety of complaints including allergies, anemia, arthritis, colds, depressions, fatigue, gastrointestinal disorders, high or low blood pressure, insomnia, headaches, obesity, pregnancy, premenstrual syndrome (PMS), respiratory conditions, and stress.
Nutritional therapy may also be involved as a complement to the allopathic treatments of cancer, diabetes, and Parkinson's disease. Other specific dietary measures include the elimination of food additives for attention deficit hyperactivity disorder (ADHD), gluten-free diets for schizophrenia, and dairy-free for chronic respiratory diseases.
A high-fiber diet helps prevent or treat the following health conditions:
A diet low in fat also promotes good health and prevents many diseases. Low-fat diets can help treat or control the following conditions:
Description
The four basic food groups, as outlined by the United States Department of Agriculture (USDA) are:
The USDA recommendation for adults is that consumption of meat, eggs, and dairy products should not exceed 20% of total daily caloric intake. The rest (80%) should be devoted to vegetables, fruits, and grains. For children age two or older, 55% of their caloric intake should be in the form of carbohydrates, 30% from fat, and 15% from proteins. In addition, saturated fat intake should not exceed 10% of total caloric intake. This low-fat, high-fiber diet is believed to promote health and help prevent many diseases, including heart disease, obesity, and cancer.
Allergenic and highly processed foods should be avoided. Highly processed foods do not contain significant amounts of essential trace minerals. Furthermore, they contain lots of fat and sugar as well as preservatives, artificial sweeteners and other additives. High consumption of these foods causes build up of unwanted chemicals in the body and should be avoided. Food allergies causes a variety of symptoms including food cravings, weight gain, bloating, and water retention. They also may worsen chronic inflammatory conditions such as arthritis.
Preparations
An enormous body of research exists in the field of nutrition. Mainstream Western medical practitioners point to studies that show that a balanced diet, based on the USDA Food Guide Pyramid, provides all of the necessary nutrients.
In 2004, the USDA was working on a revision of the Food Guide Pyramid to reflect changes in American lifestyle habits. The new eating guide was due for release in January 2005. The World Health Organization (WHO) also was weighing in on the obesity and nutrition issue, even struggling with objections from member nations that supply goods such as sugar, to endorse a global strategy in spring 2004 on diet, physical activity and health.
The Food Guide Pyramid recommends the following daily servings in six categories:
Precautions
Individuals should not change their diets without the advice of nutritional experts or health care professionals. Certain individuals, especially children, pregnant and lactating women, and chronically ill patients, only should change their diets under professional supervision.
Side effects
It is best to obtain vitamins and minerals through food sources. Excessive intake of vitamins and mineral supplements can cause serious health problems. Likewise, eating too much of one type of food, as can happen with fad diets, can be harmful. The key to nutrition is moderation. If a person feels they are short on iron, for example, he or she should not go too far to the extreme in getting more iron through diet and supplements. A 2003 report said that too much stored iron in the body has possibly been linked with heart disease, cancer and diabetes.
The following is a list of possible side effects resulting from excessive doses of vitamins and minerals:
Research and general acceptance
Due to a large volume of scientific evidence demonstrating the benefits of the low-fat, high-fiber diet in disease prevention and treatment, these recommendations have been accepted and advocated by both complementary and allopathic practitioners.
You probably know you need to eat protein, but what is it? Many foods contain protein (say: pro-teen), but the best sources are beef, poultry, fish, eggs, dairy products, nuts, seeds, and legumes like black beans and lentils. Protein builds up, maintains, and replaces the tissues in your body. (Not the tissues you blow your nose in! We mean the stuff your body's made up of.) Your muscles, your organs, and your immune system are made up mostly of protein.
Your body uses the protein you eat to make lots of specialized protein molecules that have specific jobs. For instance, your body uses protein to make hemoglobin (say: hee-muh-glow-bin), the part of red blood cells that carries oxygen to every part of your body. Other proteins are used to build cardiac muscle. What's that? Your heart! In fact, whether you're running or just hanging out, protein is doing important work like moving your legs, moving your lungs, and protecting you from disease.
All About Amino Acids
When you eat foods that contain protein, the digestive juices in your stomach and intestine go to work. They break down the protein in food into basic units, called amino acids (say uh-mee-no a-sids). The amino acids then can be reused to make the proteins your body needs to maintain muscles, bones, blood, and body organs.
Proteins are sometimes described as long necklaces with differently shaped beads. Each bead is a small amino acid. These amino acids can join together to make thousands of different proteins. Scientists have found many different amino acids in protein, but 22 of them are very important to human health.
Of those 22 amino acids, your body can make 13 of them without you ever thinking about it. Your body can't make the other nine amino acids, but you can get them by eating protein-rich foods. They are called essential amino acids because it's essential that you get them from the foods you eat.
Different Kinds of Protein
Protein from animal sources, such as meat and milk, is called complete, because it contains all nine of the essential amino acids. Most vegetable protein is considered incomplete because it lacks one or more of the essential amino acids. This can be a concern for someone who doesn't eat meat or milk products. But people who eat a vegetarian diet can still get all their essential amino acids by eating a wide variety of protein-rich vegetable foods.
For instance, you can't get all the amino acids you need from peanuts alone, but if you have peanut butter on whole-grain bread you're set. Likewise, red beans won't give you everything you need, but red beans and rice will do the trick. The good news is that you don't have to eat all the essential amino acids in every meal. As long as you have a variety of protein sources throughout the day, your body will grab what it needs from each meal.
How Much Is Enough?
You can figure out how much protein you need if you know how much you weigh. Each day, kids need to eat about 0.5 grams of protein for every pound (0.5 kilograms) they weigh. That's a gram for every 2 pounds (1 kilogram) you weigh. Your protein needs will grow as you get bigger, but then they will level off when you reach adult size. Adults, for instance, need about 60 grams per day.
To figure out your protein needs, multiply your weight in pounds times 0.5 or you can just take your weight and divide by 2. For instance, a 70-pound (or 32-kilogram) kid should have about 35 grams of protein every day. If you only know your weight in kilograms, you need about 1 gram of protein each day for every kilogram you weigh.
You can look at a food label to find out how many protein grams are in a serving. But if you're eating a balanced diet, you don't need to keep track of it. It's pretty easy to get enough protein. Here's an example of how a kid might get about 35 grams of protein in a day:
* 2 tablespoons (15 milliliters) peanut butter (7 grams protein)
* 1 cup (240 milliliters) low-fat milk (8 grams protein)
* 1 ounce (30 grams) or two domino-size pieces of cheddar cheese (7 grams protein)
* 1.5 ounces (90 grams) chicken breast (10.5 grams protein)
* ½ cup (80 grams) broccoli (2 grams protein)
Nutrament
A nutritional vitamin drink supplied by Novartis Labs, Nutrament was originally distributed by Mead Johnson & Company, beginning in 1960. Current flavors on the market are vanilla, chocolate, strawberry, coconut, banana, cappucino, Dulce De Leche Caramel and eggnog. The product is supplied as individual servings in pull-top cans. According to Novartis' website, Nutrament currently is available only in certain retail stores in New York and Florida although certain internet stores also have it available.
In official records, it is described as "Nutritionally Complete Food Consisting Principally of Milk Solids, Maltose-Dextrins, Soy Flour, Sucrose." Late in the 1960s, a powdered form was offered for mixing with milk, but that brand registration was not renewed in 1988 and officially expired in 1992, still owned by Mead Johnson.
The current formulation is made of skim milk, the sweeteners sugar and corn syrup, various vegetable oils, flavorings, and vitamins and minerals. Because of its high milk content, lactose intolerant people would need to take a enzyme supplement to digest the drink properly. For other persons, the product is considered easy to digest and is a good protein source. It has been used as a meal substitute in dieting, because of its calorie portion control.
Mead Johnson also marketed a "dietary supplement" under the same brand in 1985, and registered the brand "Nutrament The Energy and Fitness Drink" in 1996. Nutrament was purchased from Mead Johnson & Company effective February 13, 2004.
Biological significance
Vitamin C is purely the L-enantiomer of ascorbate; the opposite D-enantiomer has no physiological significance. Both forms are mirror images of the same molecular structure. When L-ascorbate, which is a strong reducing agent, carries out its reducing function, it is converted to its oxidized form, L-dehydroascorbate.[6] L-dehydroascorbate can then be reduced back to the active L-ascorbate form in the body by enzymes and glutathione.[8]
L-ascorbate is a weak sugar acid structurally related to glucose which naturally occurs either attached to a hydrogen ion, forming ascorbic acid, or to a metal ion, forming a mineral ascorbate.
