Nutrition and Constituents of Food ch 17

Niacin (also called Vitamin B3)

1.Niacin helps the body turn food into energy. It aids in digestion and is important for nerve function. 2.You find niacin in red meat, poultry, fish, fortified hot and cold cereals, and peanuts. 3.Teenage boys need 16 mg of niacin daily. Teenage girls need 14 mg a day.

Minerals

Approximately 4 percent of the body's mass consists of minerals. They are classified as trace minerals (the body requires less than 100 mg/day of these), and major minerals (the body requires more than 100 mg/day of these). Minerals can be found in water and soil and therefore in root plants and animals.

Fat

Fat serves as the storage substance for the body's extra calories. It fills the fat cells (adipose tissue) that help insulate the body. Fats are also an important energy source. When the body has used up the calories from carbohydrates, which occurs after the first 20 minutes of exercise, it begins to depend on the calories from fat. Healthy skin and hair are maintained by fat. Fat helps in the absorption, and transport through the bloodstream of the fat-soluble vitamins A, D, E, and K.

Folate (also known as Vitamin B9, folic acid, or folacin)

Folate helps the body make red blood cells, break down proteins, and keep the heart healthy. It is also needed to make DNA. Dried beans and other legumes, leafy green vegetables, asparagus, oranges and other citrus fruits, and poultry products are good sources of this vitamin. So are fortified or enriched bread, noodles, and cereals. Teenage girls and boys need 400 micrograms of folate daily. Optimal Intake: The current recommended intake for folic acid is 400 micrograms per day. There are many excellent sources of folic acid including prepared breakfast cereals, beans, and fortified grains.

Riboflavin (also called Vitamin B2)

Riboflavin is essential for turning carbohydrates into energy and producing red blood cells. It is also important for healthy vision. Some of the best sources of riboflavin are meat, eggs, legumes (like peas and lentils), nuts, dairy products, leafy green vegetables, broccoli, asparagus, and fortified cereals. Teenage boys need 1.3 mg of riboflavin per day and teenage girls need 1 mg.

Saturated Fats

Saturated fats tend to be solid at room temperature. They are the biggest dietary cause of high LDL ("bad cholesterol") levels. When looking at a food label, pay very close attention to the % of saturated fats and avoid or limit any foods that are high in (contain over 20% of) saturated fats. Saturated fats are found in animal products such as butter, cheese, whole milk, ice cream, cream, and fatty meats. They are also found in some vegetable oils such as coconut, palm, and palm kernel oils. (Note: Most other vegetable oils contain unsaturated fat and are healthy.)

Function of minerals

The basic functions of the minerals are threefold: They provide structure in forming bones and teeth.They help maintain normal heart rhythm, muscle contractility, neural conductivity, and acid-base balance. They help regulate cellular metabolism by becoming part of enzymes and hormones that modulate cellular activity.

Proteins

The basic structure of proteins is a chain of amino acids. They are the main component of muscles, organs, and glands. Every living cell and all body fluids, except bile and urine, contain proteins... All meat and other animal products are sources of complete proteins. These include beef, lamb, pork, poultry, fish, shellfish, eggs, milk, and milk products. The protein content in foods such as grains, fruits, and vegetables is incomplete protein as it lacks one or the other of the essential amino acids. Plant proteins can be combined to include all of the essential amino acids and form a complete protein. Examples of combinations which form complete plant protein sources are rice and beans, milk and wheat cereal, and corn and beans. A diet high in meat can lead to high cholesterol or other diseases such as gout. Another potential problem is that a high-protein diet may put too much strain on the kidneys. Extra waste matter, which is the end product of protein metabolism, is excreted through the urine...

Major Minerals

The major minerals needed by the body are sodium, potassium, calcium, phosphorus, magnesium, sulfur, and chlorine.

Carbohydrates

The primary function of carbohydrates is to provide energy for the body, especially the brain and the nervous system. Your liver breaks down carbohydrates into glucose (blood sugar), which is used as a source of energy by the body... 1.Simple carbohydrates (also called sugars): Simple carbohydrates can be found in white sugar, preservatives, candies, coke, cake, juice concentrates, honey, and glucose syrup. They are made up of single or double molecules and are quickly absorbed into the blood stream. 2.Complex carbohydrates: Foods that are high in complex carbohydrates include whole grain bread, pasta, rice, beans, vegetables and potatoes. They are made up of complex molecules and the body requires time to digest them, which means that we feel full for a longer period after eating them. 3.Very complex carbohydrates (also known as fiber): These carbohydrates add bulk to our food, which helps in digestion. They are found in whole meal bread and phsylum husk. Fibers help to ease the flow of food through the intestines, reduce the risk of diabetes and lower cholesterol. Thirty o thirty five grams of fiber a day is the ideal amount, which is very beneficial for the body. Very complex carbohydrates have an extremely complex molecular structure. On the other hand, deficiency of carbohydrates can lead to a lack of calories (malnutrition). Low consumption of carbohydrates can also stand in the way of making up the calories lost through work or exercise. For most people, 40% to 60% of the total calories required should come from carbohydrates, preferably from complex carbohydrates (starches) and naturally occurring sugars that can be found in fruit. Complex carbohydrates provide calories, vitamins, minerals, and fiber to the body...

Hydrogenation

The term hydrogenated refers to the hardening of oils when they mix with oxygen. Hard butter and margarine are examples of such foods. Foods made with hydrogenated oils should be avoided because they contain high levels of trans-fatty acids, which are linked to heart disease. (Look at the ingredients in the food label.) The terms "hydrogenated" and "saturated" are related; oil becomes saturated when hydrogen is added to it (i.e. when it becomes hydrogenated). Eating too much saturated fat is one of the major risk factors responsible for heart disease. A diet high in saturated fat causes a soft, waxy substance called cholesterol to build up in the arteries. Too much fat also increases the risk of heart disease because of its high calorie content, which increases the chance of becoming obese (another risk factor responsible for heart disease and some types of cancer). A large intake of polyunsaturated fat may increase the risk of some types of cancer. Eat foods that are naturally low in fat -- whole grains, fruit, and vegetables. Get plenty of soluble fiber with oats, bran, dry peas, beans, cereal, and rice. Limit your consumption of fried foods, processed foods, and commercially prepared baked goods (donuts, cookies, crackers).

Trace Minerals

The trace minerals needed by the body are iron, zinc, copper, selenium, iodine, fluorine, and chromium.

Trans-Fatty Acids

These fats form when vegetable oil hardens (is hydrogenated). They can raise LDL levels. They can also lower HDL ("good cholesterol") levels. Trans-fatty acids are found in fried foods, baked commercial goods (donuts, cookies, crackers etc.), processed foods, and margarine.

Thiamin (also called Vitamin B1)

Thiamin helps the body convert carbohydrates into energy and is necessary for the heart, the muscles, and the nervous system to function properly. People get thiamin from many different foods including fortified breads, cereals, and pasta; meat and fish; dried beans, soya foods, and peas; and whole grains like wheat germ. Teenage boys need 1.2 mg of thiamin each day while teenage girls need 1 mg.

Unsaturated Fats

Unsaturated fats tend to be liquid at room temperature. 1.Monounsaturated fats help lower blood cholesterol if used in place of saturated fats. However, monounsaturated fats have a lot of calories. So you still need to limit their consumption. Examples include olive and canola oils. 2. Polyunsaturated fats also help lower blood cholesterol if used in place of saturated fats. However, polyunsaturated fats also have a lot of calories. So you still need to limit their consumption. Examples include safflower, sunflower, corn, and soybean oils.

Vitamin A

Vitamin A prevents eye problems, promotes a healthy immune system, is essential for the growth and development of cells, and keeps the skin healthy.Good sources of vitamin A are milk, eggs, liver, fortified cereals, dark colored orange, green vegetables (such as carrots, sweet potatoes, pumpkin, and kale), and orange colored fruits such as cantaloupe, apricots, peaches, papayas, and mangoes. Teenage boys need 900 micrograms of vitamin A each day whereas teenage girls need 700 migrograms. Optimal Intake: The current recommended intake of vitamin A is 5,000 IU for men and 4,000 IU for women. Many breakfast cereals, juices, dairy products, and other foods are fortified with vitamin A. Many fruits and vegetables, and some supplements also contain beta-carotene and other vitamin A precursors, which the body can turn into vitamin A.

Vitamin B12

Vitamin B12 helps build DNA, make red blood cells, and is important for nerve cell function. Vitamin B12 is found naturally in fish, red meat, poultry, milk, cheese, and eggs. It is also added to some breakfast cereals. Teenagers should get 2.4 micrograms of vitamin B12 daily.Optimal intake: The current recommended intake for vitamin B12 is 6 micrograms per day. Around 100 years ago, the lack of vitamin B12 was the cause of a common and deadly disease called pernicious anemia. Its symptoms include memory loss, disorientation, hallucinations, and tingling in the arms and legs. Although full-blown pernicious anemia is less common today, it is still often diagnosed in older people who have difficulty absorbing vitamin B12 from food. It's also possible that some people diagnosed with dementia or Alzheimer's disease, are actually suffering from a more reversible vitamin B12 deficiency.

Vitamin B6

Vitamin B6 is important for the brain and nerves to function normally. It also helps the body break down proteins and make red blood cells. A wide variety of foods contain vitamin B6, including potatoes, bananas, beans, seeds, nuts, red meat, poultry, fish, eggs, spinach, and fortified cereals. Teenage boys need 1.3 mg of vitamin B6 daily and teenage girls need 1.2 mg. Optimal Intake: A healthy diet should include 1.3 to 1.7 milligrams of vitamin B6. Higher doses have been tested as a treatment for conditions ranging from premenstrual syndrome to attention deficit disorder and carpal tunnel syndrome. To date, there is little evidence that it works.

Vitamin C

Vitamin C is needed to form collagen, a tissue that helps hold cells together. It is essential for healthy bones, teeth, gums, and blood vessels. It helps the body absorb iron and calcium, aids in wound healing, and contributes to brain function. You will find high levels of vitamin C in red berries, kiwifruit, red and green bell peppers, tomatoes, broccoli, spinach, and juices made from guava, grapefruit, and orange. Teenage boys need 75 milligrams (1 milligram equals 1,000 micrograms) of vitamin C a day and teenage girls need 65 milligrams. Optimal intake: The current recommended dietary intake of vitamin C is 90 mg for men and 75 mg for women (Add an extra 35 mg for smokers). There is no good evidence to prove that mega-doses of vitamin C improve health. As evidence continues to unfold, 200 to 300 mg of vitamin C a day appears to be a good target. This is easy to hit with a good diet and a standard multivitamin. Excellent food sources of vitamin C are citrus fruits or citrus juices, berries, green and red peppers, tomatoes, broccoli, and spinach. Many breakfast cereals are also fortified with vitamin C.

Vitamin D

Vitamin D strengthens the bones because it helps the body absorb bone building calcium. Vitamin D is produced by the body when sunlight falls on the skin. You can also get vitamin D from egg yolks, fish oils, and fortified foods like milk. Teenagers need 5 micrograms of vitamin D from food every day. Optimal intake: The current recommended intake of vitamin D is 5 micrograms up to the age of 50, 10 micrograms between the ages of 51 and 70, and 15 micrograms after 70. Very few foods naturally contain vitamin D. Good sources of vitamin D include dairy products and breakfast cereals fortified with vitamin D, and fatty fish such as salmon and tuna. For most people, the best way to get the recommended daily intake is by taking a multivitamin.

Vitamin E

Vitamin E is an antioxidant and helps protect cells from damage. It is also important for the health of red blood cells. Vitamin E is found in many foods such as vegetable oils, nuts, and green leafy vegetables. Avocados, wheat germ, and whole grains are also good sources of vitamin E. Teenage boys and girls need 15 mg of vitamin E every day. Optimal intake: The recommended daily intake of vitamin E from food now stands at 15 milligrams. That is equivalent to 22 IU from natural-source vitamin E or 33 IUs of the synthetic form. Research on the body's need for vitamin E and its sources is still going on. Evidence from observational studies suggests that at least 400 IU of vitamin E per day, and possibly more, is needed for optimal health. Since standard multivitamins usually contain around 30 IU, a separate vitamin E supplement is needed to achieve this level.

Vitamin K

Vitamin K helps make six of the 13 proteins needed for blood clotting. Its role in maintaining the clotting cascade is so important that people who take anticoagulants such as Warfarin (Coumadin) must be careful to keep their vitamin K intake stable. Lately, researchers have demonstrated that vitamin K is also involved in building bone material. Low levels of circulating vitamin K have been linked to low bone density, and supplementation with vitamin K shows improvements in the biochemical measures of improving bone health. Optimal Intake: The recommended daily intake for vitamin K is 80 micrograms for men and 65 for women. Because this vitamin is found in so many foods, especially green leafy vegetables and commonly used cooking oils, most adults get enough of it. According to a 1996 survey, though, a substantial number of Americans, particularly children and young adults, are not getting the amount of the K they need.