Nutrition

Introduction
Variety, Balance, and Moderation
Vitamins
Minerals
Proteins
Carbohydrates
Fats
Water

Food provides the energy and nutrients you need to be healthy. Nutrients include proteins, carbohydrates, fats, vitamins, minerals and water. Good nutrition is one of the keys to good health. This means making sure you regularly eat foods that have a lot of vitamins and minerals in them, as well as foods that are not high in fat

• Eat a variety of foods, including vegetables, fruits and whole-grain products
• Eat lean meats, poultry, fish, beans and low-fat dairy products
• Drink lots of water
• Go easy on the salt, sugar, alcohol, saturated fat and trans fat
• Saturated fats are usually fats that come from animals. Look for trans fat on the labels of processed foods, margarines and shortenings.

There is no secret to healthy eating. Be sure to eat a variety of foods, including plenty of vegetables, fruits, and whole grain products. Also include low-fat or non-fat dairy products, lean meats, poultry, fish, and legumes. Drink lots of water and go easy on the salt, sugar, alcohol, and saturated fat. Good nutrition should be part of an overall healthy lifestyle, that also includes regular physical activity, not smoking, and stress management. If you drink alcoholic beverages, do so in moderation.

Parents everywhere face barriers that make it tough to ensure their daughters get enough weight-bearing physical activity and calcium. Turn challenges into opportunities to help yourself and your family get enough weight-bearing physical activity and calcium for strong bones.

Vitamins are natural substances found in plants and animals. Your body uses these substances to stay healthy and support its many functions. There are two types of vitamins: water-soluble and fat-soluble.

Water-soluble vitamins are easily absorbed by your body. Unlike fat-soluble vitamins, they don’t have to be absorbed using bile acids (fluids used to digest fats). Your body doesn’t store large amounts of water-soluble vitamins. The water-soluble vitamins you don’t need are removed by your kidneys and come out in your urine.

Your body has to use bile acids to absorb fat-soluble vitamins. Once these vitamins are absorbed, your body stores them in body fat. When you need them, your body takes them out of storage to be used. Eating fats or oils that are not digested can cause shortages of fat-soluble vitamins. This includes using mineral oil frequently to treat constipation or eating the fat substitute Olestra.

A standard multivitamin supplement doesn't come close to making up for an unhealthy diet. It provides a dozen or so of the vitamins known to maintain health, a mere shadow of what's available from eating plenty of fruits, vegetables, and whole grains. Instead, a daily multivitamin provides a sort of nutritional safety net.

While most people get enough vitamins to avoid the classic deficiency diseases, relatively few get enough of five key vitamins that may be important in preventing several chronic diseases. These include:

Minerals come from the earth or from water. Plants and animals absorb them to get nutrients.

The best way to get the vitamins and minerals your body needs is from the food you eat. Most people don’t need to take additional vitamin and mineral supplements. You should never take extra vitamins and minerals without talking to your doctor first. However, your doctor may suggest taking extra vitamins or minerals if you have certain health problems. You also may need more vitamins and minerals at certain times in your life, such as the following:

If you are a woman and are trying to get pregnant, your doctor will likely suggest you take a pill that contains folic acid. Women who don't get enough folic acid during pregnancy are more likely to have a baby with neural tube defects (serious problems of the brain or spinal cord). It's important to take folic acid before becoming pregnant because these problems develop very early in pregnancy.

If you’re pregnant or breastfeeding, your doctor may suggest that you take a prenatal mineral and vitamin pill that includes iron to protect you against anemia, calcium to keep your bones strong and folic acid.

If you’re a woman and are at risk of osteoporosis, your doctor may suggest that you take a calcium supplement to support the health of your bones.

If you eat a vegetarian or vegan diet (a diet that limits the animal products you eat), your doctor may suggest that you take a vitamin B12 supplement.

Vitamins and minerals aren’t dangerous unless you get too much of them. It would be hard to “overdose” on vitamins or minerals that you get from the foods you eat. But if you take supplements, you can easily take too much. This is even more of a risk if you take fat-soluble vitamins.

Sometimes, taking too much of a vitamin or mineral can lead to problems side effects. Taking too much can also cause problems with some medical tests or get in the way of how some drugs work. It’s very important to talk with your doctor before you take any vitamin and mineral pills, especially if you take prescription medicines, have any health problems or are elderly.

Proteins are complex organic compounds. The basic structure of protein is a chain of amino acids. Protein is the main component of muscles, organs, and glands. Every living cell and all body fluids, except bile and urine, contain protein. The cells of muscles, tendons, and ligaments are maintained with protein. Children and adolescents require protein for growth and development.

Proteins are described as essential and nonessential proteins or amino acids. The human body requires approximately 20 amino acids for the synthesis of its proteins. The body can make only 13 of the amino acids -- these are known as the nonessential amino acids. They are called non-essential because the body can make them and does not need to get them from the diet. There are 9 essential amino acids that are obtained only from food, and not made in the body.

If the protein in a food supplies enough of the essential amino acids, it is called a complete protein. If the protein of a food does not supply all the essential amino acids, it is called an incomplete protein. All meat and other animal products are sources of complete proteins. These include beef, lamb, pork, poultry, fish, shellfish, eggs, milk, and milk products.

Protein in foods (such as grains, fruits, and vegetables) are either low, incomplete protein or lack one of the essential amino acids. These food sources are considered incomplete proteins. Plant proteins can be combined to include all of the essential amino acids and form a complete protein. Examples of combined, complete plant proteins are rice and beans, milk and wheat cereal, and corn and beans.

A diet high in meat could lead to high cholesterol or other diseases, such as gout. Another potential problem is that a high-protein diet may put a strain on the kidneys. Extra waste matter, which is the end product of protein metabolism, is excreted in the urine. A nutritionally balanced diet provides adequate protein. Vegetarians are able to get enough protein if they eat the proper combination of plant proteins. The amount of recommended daily protein depends upon age, medical conditions, and the type of diet one is following. Two to three servings of protein-rich food will meet the daily needs of most adults.

Carbohydrates come from a wide array of foods - bread, beans, milk, popcorn, potatoes, cookies, spaghetti, corn, and cherry pie. They also come in a variety of forms. The most common and abundant are sugars, fibers, and starches. The basic building block of a carbohydrate is a sugar molecule, a simple union of carbon, hydrogen, and oxygen. Starches and fibers are essentially chains of sugar molecules. Some contains hundreds of sugars. Some chains are straight, others branch wildly.

Carbohydrates were once grouped into two main categories. Simple carbohydrates included sugars such as fruit sugar (fructose), corn or grape sugar (dextrose or glucose), and table sugar (sucrose). Complex carbohydrates included everything made of three or more linked sugars. Simple sugars were considered bad and complex carbohydrates good. The picture is much more complicated than that.

The digestive system handles all carbohydrates in much the same way - it breaks them down (or tries to break them down) into single sugar molecules, since only these are small enough to cross into the bloodstream. It also converts most digestible carbohydrates into glucose (also known as blood sugar), because cells are designed to use this as a universal energy source.

Fiber is an exception. It is put together in such a way that it can't be broken down into sugar molecules, and so passes through the body undigested.

• Fiber content. Fiber shields the starchy carbohydrates in food immediate and rapid attack by digestive enzymes. This slows the release of sugar molecules into the bloodstream.
• Ripeness. Ripe fruits and vegetables tend to have more sugar than unripe ones, and so tend to have a higher glycemic index.
• Type of starch. Starch comes in many different configurations. Some are easier to break into sugar molecules than others. The starch in potatoes, for example, is digested and absorbed into the bloodstream relatively quickly.
• Fat content and acid content. The more fat or acid a food contains, the slower its carbohydrates are converted to sugar and absorbed into the bloodstream. Physical form. Finely ground grain is more rapidly digested, and so has a higher glycemic index, than more coarsely ground grain.

All these elements lead to sometimes counterintuitive results. Some foods that contain complex carbohydrates, such as potatoes, quickly raise blood sugar levels, while some foods that contain simple carbohydrates, such as whole fruit, raise blood sugar levels more slowly.

Digestible carbohydrates are broken down in the intestine into their simplest form, sugar, which then enters the blood. As blood sugar levels rise, special cells in the pancreas churn out more and more insulin, a hormone that signals cells to absorb blood sugar for energy or storage. As cells sponge up blood sugar, its levels in the bloodstream fall back to a preset minimum. So do insulin levels.

For optimal health, get your grains intact from foods such as whole wheat bread, brown rice, whole-grain pasta, and other possibly unfamiliar grains like quinoa, whole oats, and bulgur. Not only will these foods help protect you against a range of chronic diseases, they can also please your palate and your eyes.

Fat is a major source of energy and aids your body in absorbing vitamins. It's important for proper growth, development and keeping you healthy. Fat provides taste to foods and helps you feel full. Fats are an especially important source of calories and nutrients for infants and toddlers. Dietary fat also plays a major role in your cholesterol levels.

• Saturated fats such as butter, solid shortening, lard and fatback
• Trans fats, found in vegetable shortenings, some margarines, crackers, cookies, snack foods and other foods made with or fried in partially hydrogenated oils

Try to replace them with oils such as corn, canola, olive, safflower, soybean and sunflower. Of course, eating too much fat will put on the pounds.

Every living creature needs clean and safe drinking water. How much do you need? It depends - your size, activity level and the weather all make a difference.

The water you drink is a combination of surface water and groundwater. Surface water includes rivers, lakes and reservoirs. Groundwater comes from underground. The United States has one of the safest water supplies in the world, but drinking water quality can vary from place to place. It depends on the condition of the source water and the treatment it receives. Treatment may include adding fluoride to prevent cavities and chlorine to kill germs.

Your water supplier must give you annual reports on drinking water. The reports include where your water came from and what contaminants are in it.