Nutrition (2165 words)
NutritionMost people know that good nutrition is important for good health. Recommended
Dietary Allowances (RDA) are the daily amounts of essential nutrients that will prevent
deficiencies in most healthy people. But not many people realize the importance a healthy
diet can have on their health for years to come. To help us stay healthy a person should
eat a variety of foods, maintain ideal weight, avoid too much fat, and eat foods with
enough starch and fiber. A good diet helps children grow, develop, and do well in school.
It also helps young and older adults to work productively and feel their best. A healthy
diet can also lessen the risk factors for obesity and high blood pressure. For our benefit,
the U.S. Department of Health and Human Services and the U.S. Department of
Agriculture has issued Dietary Guidelines. These guidelines are designed to help
Americans choose the recommended number of daily servings from each of the five
different food groups; Bread, Meat, Vegetable, Fruit, and Dairy. The Nutrition Facts
Label is made to help you buy foods that will meet the Dietary Guidelines. Most
processed foods now carry nutrition information.
People need energy and essential nutrients. These nutrients are essential because the
body cannot make them and has to get them from food. Energy needs vary by age. Adults
need less food than younger and more active individuals. People who are less active or are
trying to lose weight will eat less food and have problems meeting their nutrient needs.
Almost all Americans need to be more active, because an inactive lifestyle is unhealthy. In
order to stay at the same body weight, people need to balance the amount of energy in
food with the amount of energy the body uses. People need to put more energy into daily
activities. The pattern of eating is also important. Snacks provide a large amount of
calories for many Americans. Unless nutritious snacks are part of the daily diet, snacking
will cause weight gain. Also binge eating and fasting will add to weight problems.
Maintaining weight in older people is important because they usually lose weight as they
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age. Some of that weight is muscle. People need to exercise regularly to maintain muscle,
to feel better and to reduce the risk of falls and broken bones.
The quality and variety of food in the United States allow almost everyone to have a
nutritious diet. Nutrients are divided into five major groups; proteins, carbohydrates, fats,
vitamins and minerals. Each of these food components have a special function in the body,
and all of them together are needed for overall health. The body uses energy to function
and keep itself at a constant temperature. Scientists have been able to find out that the
body gets its fuel from carbohydrates, fats, and protein.
Carbohydrates
Carbohydrates are the most available foods in the world. Carbohydrates in foods, like
whole grain breads and cereals, provide calories and nutrients and also increase dietary
fiber. Dietary fiber, like lettuce, if eaten daily, can decrease the risk of colon cancer. If
there isn’t enough carbohydrates in the body during exercise, the body tires faster.
Research has proven that a daily diet high in carbohydrates is helpful. Most sports
nutritionists recommend a meal high in carbohydrates 3 or 4 hours before an event.
Carbohydrates provide most of the energy in almost all people’s diets. The best sources
for carbohydrates are grains, potatoes, vegetables, and fruits.
Fats
Everyone thinks that fat in the diet is bad, but really the body needs it. Fat provides
energy by giving calories to the body. They are the most concentrated source of energy in
the diet. People need to watch how much fat they eat, not do without it entirely. Because
fat sources have little water in them, they take up less room, so we eat more fat without
getting full. So that’s why it is easy to get fat on a high-fat diet. Obesity increases the risk
for high blood pressure and eventually for stroke. It is also associated with heart disease.
There is evidence that certain kinds of cancer like colon, lung, and bladder cancer run in
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people who have high-fat diets. It is also known that breast and uterine cancer are more
common in obese women. Best sources of fat are margarine, vegetable/plant oils, nuts,
meats, cheese, and cream.
Protein
The main purpose of protein in the body is to build and repair tissues. Most of the
body’s protein is located in the muscle tissue. Every cell in the body is partly made of
proteins. As a child grows, his muscles are built from proteins. A person with burns or
open sores need protein to heal these wounds. Also, if carbohydrates, starches, or fats are
unavailable, protein can be used to supply energy. Everyone needs some protein
everyday. How much is needed depends on body size, rate of growth, and each persons
healing requirements. The best sources of protein are eggs, milk, fish, meat, poultry, and
nuts.
Vitamins
Vitamins help your body use carbohydrates, fats, and proteins. In most cases, vitamins
cannot be made by the body and must be taken from food. Vitamins are necessary for
growth, healthy skin, teeth and eyes, and cell formation. They are also important in
digestion, mental alertness, and resistance to bacterial infections. All natural vitamins are
found only in living things, plants and animals. Good sources of vitamins are meat, fish,
poultry, milk, fruit, breads, and cereals. There are 13 known vitamins, 4 fat-soluble and 9
water-soluble vitamins. Fat-soluble vitamins include vitamins A, D, E, and K. The water-
soluble vitamins include vitamin C and the B-vitamin complex.
A lot of people think vitamins can replace food. They cannot. If you eat a variety of
nutritious foods, you shouldn’t need vitamin supplements. Taking more nutrients than your
body needs won’t give you any more energy, but will prevent nutritional deficiency
diseases like scurvy, beriberi, and rickets, although these diseases are rare in the United
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States. Taking vitamin and mineral supplements to prevent or give you more protection
against cancer has not been proven effective. It has been found that smoking slightly
increases the body’s need for vitamin C, but not for nutrients over the 100% of the
Recommended Dietary Allowances. High-potency vitamin/mineral combinations could be
dangerous if taken in large amounts. Some side effects are fatigue, diarrhea, and hair loss.
More serious effects are kidney stones, liver or nerve damage, or even death. If
supplements are dangerous, why are they being sold? Our laws do not allow the United
States Food and Drug Administration to limit the amount of nutrients that go into a single
pill.
Water
You won’t find water listed on nutrient charts, but everyone knows that we can’t live
without it. While we can survive for long periods of time without many vitamins and
minerals, it takes only a few days without water to lead to death. Water is a colorless
compound of hydrogen and oxygen that almost every cell in the body needs to survive, it
contains no calories. Even tissues that are not thought of as watery contain large
amounts of water. Water makes up about three-fourths of the brain and muscles, and bone
is more than one-fifth water. In all, water accounts for about one-half to two-thirds of the
body’s makeup.
One of water’s many important jobs is to carry nutrients and oxygen to all parts of the
body through the blood and lymphatic systems. Also, it plays an important role in
regulating body temperature; the heat released when we lose water through perspiration
helps keep us cool.
We cannot rely on thirst as the only indicator of water requirements. It is possible to
quench your thirst without putting back into your body the amount of water you need.
That’s the reason you’re advised to drink 6 to 8 glassed of fluid every day, whether you’re
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thirsty or not. This recommendation has special meaning for the elderly, they are less
likely to get thirst signals when their bodies need water. Drinking water past the point of
thirst also lessens the risk of dehydration for people who live in really hot climates, or
athletes and laborers who sweat all the time. It’s almost impossible to take in too much
water, since the body is very efficient at getting rid of what it doesn’t need.
Most of the water we drink comes from beverages, including juice, milk, and soft
drinks. Coffee and tea also supply water, but these sources are taken daily and they
increase loss of water through the kidneys. Solid foods also add a lot to our daily water
intake. Most fruits are more than 80 percent water, and even foods that don’t seem juicy
or moist supply us with large amounts of water.
Minerals
Minerals are necessary for good health and growth. Certain amounts of minerals are
needed to keep our bodies working properly.
The two important body functions that mineral elements do are building and regulating.
The building functions have to do with the skeleton and all soft tissues, including the
blood. The regulating functions include heartbeat, blood clotting, maintenance of blood
pressure, water balance, nerve responses, and carrier of oxygen from the lungs to tissues.
Large amounts of some minerals are needed in the diet because they are present in large
amounts in the body. These minerals – calcium, phosphorus, sodium, chloride, potassium,
magnesium and sulphur are known as macrominerals. More than 100 milligrams of these
minerals are needed everyday. Others, called trace minerals, are needed in small amounts.
These are iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium. Some
mineral elements are considered harmful, such as lead, mercury and cadmium.
Phosphorus helps strengthen bones and teeth and is also a part of every body tissue. It
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has more functions than any other mineral element. Antacids can interfere with
phosphorus absorption. If used for a long time antacids could cause severe bone
demineralization. Good sources of phosphorus are meat, fish, poultry and eggs. Fruits and
vegetables are usually low in phosphorus and are not good sources.
Potassium is necessary for the fluid inside body cells. It helps control muscle action
and transfer of nerve impulses. Prolonged vomiting and kidney disease will cause
potassium deficiencies. The best sources of potassium are fruits and vegetables.
Sodium is found mainly in the blood and fluids outside body cells. It maintains water
balance inside and outside the cells. The sending of nerve impulses also depends on the
proper amounts of sodium. Doctors will often advise patients to reduce the amount of salt
in their diet in cases of high blood pressure, kidney disease, cirrhosis of the liver and
congestive heart disease. A decrease in salt can reduce water holding, which usually is
associated with these health problems.
Magnesium is important to the normal functioning of nerves and muscles. When there
is not enough magnesium in the body, people could have symptoms like muscle spasms,
weakness, irregular heart beat, and leg cramps. In malnourished people, a lack of
magnesium will cause tremors and convulsions.
Since there are too many vitamins and minerals to research in full, I have listed below
the essential ones and what each one does for the body.
Vitamin A: Promotes good eyesight and helps keep the skin and mucous membranes
resistant to infection.
Vitamin B1: (thiamine) – Prevents beriberi. Important to carbohydrate energy and health
of nervous system.
Vitamin B2: (riboflavin) – Protects skin, mouth, eyes, eyelids, and mucous membranes.
Vitamin B6: (pyrido xine) – Important in the regulation of the central nervous system.
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Vitamin B12: (cobalamin) – Needed to form red blood cells.
Niacin: Maintains the health of skin, tongue, and digestive system.
Folic acid: (folacin) – Required for normal blood cell formation, growth, and
reproduction.
Other B Vitamins: biotin, pantothenic acid.
Vitamin C: (ascorbic acid) – Maintains collagen, a protein necessary for the formation of
skin, ligaments, and bones. It helps heal wounds, and mend fractures and aids in resisting
some types of viral and bacterial infections.
Vitamin D: Important for bone development.
Vitamin E: (tocopherol) – Helps protect red blood cells.
Vitamin K: Necessary for formation of prothrombin, which helps blood to clot.
Vegetarians
Some Americans eat vegetarian diets for reason of culture, religious beliefs, health,
dislike of meat, compassion for animals, and belief in non-violence. Most vegetarians eat
dairy products and eggs, and have excellent health. Vegetarian diets meet with the
Dietary Guidelines and can meet all known nutrient needs. The key to a healthy
vegetarian diet is to eat a wide variety of foods including fruits, plenty of green leafy
vegetables, whole grain products, nuts, and seeds. Because animal products are the only
sources of vitamin B-12, vegetarians must supplement their diet with this vitamin. Also
vegetarian diets, especially for children, need to have the right amount of vitamin D and
calcium, which comes from dairy products.
In the eighteenth century, scientists learned more about how food helped the body
work. And in the twentieth century, vitamins were discovered as essential elements in the
human diet. So much is known about nutrition today it’s hard to believe that 100 years ago
rickets was a common disease for young people, lack of iron for the wealthy, and cavities
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were a part of life for children. Two hundred years ago, the average life expectancy was
35 years. One hundred years ago, it was 40 years. Today, with all our medical advances
and knowledge of nutrition the life expectancy could be 75 years. But even with this
knowledge Americans still continue to eat too much food that is too high in fat,
cholesterol, sugar, and salt!
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