Nutrition is the science that deals with food and how the body uses it. All living things need food to live. The food supplies energy, which people need to perform certain actions. Food also provides substances that the body needs to build and repair its tissues and to regulate its organs and organ systems. Food provides certain chemical substances needed in order for a person to maintain good health. These chemical substances are called nutrients. Nutrients can perform three important functions. They provide materials for building, repairing, or maintaining body tissues. They help regulate body processes. They serve as fuel to provide energy. The body needs energy to maintain all its functions. People who do not get enough nutrients are sometimes lazy and are unwilling to work. The foods we eat contain thousands of different chemicals. Our body, however, only needs only a few dozen of these chemicals in order to stay healthy. These are the nutrients that the body needs. Nutrients are divided into six main groups. They are (1)water, (2)carbohydrates, (3)fats, (4)proteins, (5)minerals, (6)vitamins. Water, carbohydrates, fats, and proteins are called macronutrients. Since macro means large, the body needs these four nutrients in large amounts.
Minerals and vitamins are called micronutrients (because micro means small). The body needs only small amounts of these nutrients. Water is the most important nutrient. Our bodies can survive without other nutrients for several weeks, but we can only go without water for about one week. Water is needed in great amounts because the body consists largely of water. Between 50 and 75 percent of a normal person’s body weight is made up of water. The body needs water to carry out all of its life processes. Watery solutions help dissolve other nutrients and carry them to all of the tissues. The body also needs water to carry away waste products and to cool itself. Adults should drink about 2 1/2 quarts of water every day. The carbohydrates, fats, and proteins are needed because they have nutrients which provide energy. Carbohydrates include all sugars and starches. They are the main source of energy for living things.
There are two types of carbohydrates, simple and complex. Simple carbohydrates include sugars and have a simple molecular structure. Complex carbohydrates include starches and have a larger and more complicated molecular structure. The structure consists of many simple carbohydrates linked together. Fats are a highly concentrated source of energy. All fats are composed of an alcohol called glycerol and substances called fatty acids. A fatty acid consists of a long chain of carbon atoms. There are three types of fatty acids. They are saturated, monounsaturated, and polysaturated. This is a chart that describes the amount of fat per serving. The bold words can be found on many food products in the supermarket. Fat free: less than 0.5 grams of fat per serving Saturated fat free: less than 0.5 grams of saturated fat per serving, and the level of trans fatty acids does not exceed 1% of total fat Low fat: 3 gram or less per serving and, if the serving is 30 grams or less or 2 tablespoons or less, per 50 grams of the food Low saturated fat: 1 grams or less per serving and not more than 15% of calories from saturated fatty acids Reduced or Less fat: at least 25% less per serving than compared food Proteins serve as one of the main building materials for the body.
Skin, cartilage, muscle, and hair are made up largely of proteins. Protein also contains enzymes which speed up chemical reactions. Cells could not function without these enzymes. Proteins also serve as hormones (chemical messengers) and as antibodies (disease fighting chemicals). Proteins are large, complex molecules made up of smaller units called amino acids. The body must have a sufficient supply of twenty amino acids. It can produce eleven of them in sufficient amounts. The nine others are called essential amino acids. The body cannot make these amino acids. They must come from food. The best sources of protein are cheese, eggs, lean meat, fish, and milk. The proteins in these foods are called complete proteins. They are called this because they contain adequate amounts of all the essential amino acids. Cereal grains, legumes (plants of the pea family), vegetables, and nuts also supply proteins to the body.
These proteins are called incomplete proteins because they do not have adequate amounts of one or more of the essential amino acids. Although the vitamins and minerals are only needed in small amounts, they are still important to the body. Minerals are needed for growth, to maintain tissues, to regulate body functions, and maintenance of body structures. These minerals are not to be confused with rock minerals. Minerals are inorganic compounds. This means that they are not created by living things. The required minerals are calcium, magnesium, phosphorus chlorine, potassium, sodium, and sulfur. Calcium, magnesium, and phosphorus are important for the bones and the teeth. Calcium, which is mostly found in milk products, is also necessary for blood clotting. Cereals and meats provide phosphorus. Whole grain cereals, nuts, and lettuce, are good sources of magnesium. People need only small amounts of minerals each day.
Vitamins are needed in order for a person to have good health. Vitamins regulate chemical reactions by which the body converts food into energy and tissues. There are 13 vitamins. The main vitamins are A, B-1, B-2, B-12, C, D, E, and K. Vitamin A is necessary for healthy skin and development of the bones. This vitamin can be found in liver, green and yellow vegetables, and milk. Vitamin B-1 is necessary for changing starches and sugars into energy. It is found in meat and whole grain cereals. Vitamin B-2 is needed for complicated chemical reactions that take place during the body’s use of food. This is found in milk, cheese, fish, liver, and green vegetables. Vitamin B-12 is needed for forming red blood cells and for a healthy nervous system. B-12 is found in animal products such as liver. Vitamin C is needed for the maintenance of the ligaments, tendons, and other supportive tissues. Vitamin C is found in fruits and potatoes.
Vitamin D is necessary for the body’s use of calcium. Vitamin D is found in milk and fish. Vitamin E helps maintain cell membranes. It is found in vegetable oils, whole grain cereals, meats, fruits, and vegetables. Vitamin K is necessary for blood clotting and is found in lettuce. A balanced diet is the key to having good health. A balanced diet includes every kind of nutrient. The food we eat directly effects our health. A good diet will help prevent certain illnesses and help in the recovery from others. An improper diet increases the risk of various diseases. Nutrition experts recommend that the daily diet include a certain number of servings from each of the five food groups: (1) vegetables, (2) fruits, (3) breads, cereals, rice, and pasta, (4) milk, yogurt, and cheese, and (5) meat, poultry, fish, dried beans and peas, eggs, and nuts. Energy is important for people to get through their day. The amount of energy varies for every person.
A person who plays sports needs more calories than someone who does little physical work. Children need more calories than their size would indicate because they are growing. Pregnant women need extra calories in order to provide enough nutrients for a healthy baby. Health experts recommend that people limit their intake of saturated fats and cholesterol. The consumption of saturated fats and cholesterol raises the level of cholesterol in a person blood. A high level of blood cholesterol increases the risk of heart disease. Animal products are the source of most saturated fats and all dietary cholesterol. People should eat lean meats, fish, poultry, and low fat dairy products to reduce the consumption of saturated fats and cholesterol. People should also limit their intake of sodium and sugar. A diet that includes a great deal of sodium may increase the risk of high blood pressure. Sodium is found in many foods. It can be found in fast food (Kentucky Fried Chicken has great tasting fast food chicken but it is very unhealthy), junk/snack food (my favorite), canned foods, and TV dinners.
Fresh foods have much less sodium than most frozen foods. Foods that have a lot of sugar are often high in calories and fat but low in minerals, proteins, and vitamins. These foods are sometimes called “empty calorie” foods because they make a person feel full but provide few nutrients. The sugars are bad because they contribute to tooth decay and cavities. Foods with a lot of sugar are candies, pastries, and breakfast cereals. Instead of eating sugary foods, people should eat fresh fruits and vegetables. A bad drink to have is alcohol. Alcoholic beverages supply calories, but they provide almost no nutrients. Alcohol is also a powerful drug, and constant drinking can lead to health problems. If people drink alcohol, they should drink only small amounts at a time. Children, adolescents, and pregnant women should not drink alcohol at all. Also, people who are about to drive should never drink alcohol. If a person wants to stay thin they should not overeat. When a person consumes more calories than are needed, the body stores most of the excess calories as fat. This can result in OBESITY.
An obese person has too much body fat for good health. To avoid obesity, people should be careful not to use food as a reward or as a way to overcome loneliness or boredom. It is also a good idea to avoid snacking on foods that are high in fat or sugar. Also try exercising and eating fruits and vegetables. An improper or inadequate diet can lead to a number of diseases. A bad disease to get is heart disease. Heart disease is the narrowing of the coronary arteries and it reduces the blood supply to the heart. It can lead to chest pain and heart attacks. The main causes of heart disease are high blood pressure and high cholesterol. This disease can be avoided by eating nutritional foods. Another disease is malnutrition. Malnutrition is a condition caused by a deficiency or excess of essential nutrients, causing many health problems, including extreme weight loss, stunted growth, and weakened resistance to infection.
Severe malnutrition can lead to death. Here are some recipes for snacks that are easy to make. Crispix Mix Original Recipe 7 cups Crispix cereal 1 cup mixed nuts 1 cup pretzels 3 tablespoons margarine, melted 1/4 teaspoon garlic salt 1/4 teaspoon onion salt 2 teaspoon lemon salt 4 teaspoon Worcestershire Sauce 1. Combine Cripix cereal, nuts and pretzels in a 13 x 9 x 2 inch baking pan. Set aside. 2. Stir together remaining ingredients. Gently stir spices and margarine into cereal mixture until evenly coated.
3. Bake at 250 degrees for about 45 minutes, stirring every 15 minutes. Spread on paper towels to cool. Store in ziploc storage bags. Serves 10 to 12 Rice Krispies Treats 3 tablespoons margarine 1 package (about 40) regular marshmallows or 4 cups miniature marshmallows 6 cups Rice Krispies cereal Vegetable cooking spray 1. Melt It. Melt margarine in large saucepan over low heat. Add marshmallows and stir until completely melted. Remove from heat. 2. Mix It. Add Rice Krispies cereal. Stir until well coated. 3. Spread It. Using buttered spatula or waxed paper, press mixture evenly into 13 x 9 x 2 inch pan coated with cooking spray. Cut into 2 x 2 inch squares when cool. Makes 24 squares
Garrison, Robert H., Jr. The Nutrition Desk Reference. New York: Keats Pub., 1990 Stare, Fredrick J. Your Guide to Good Nutrition. Chicago: Prometheus, 1991 Kellogg’s Rice Krispies box. Side panel. Exp. Sep 08 1998. Winick, Myron. The Columbia Encyclopedia of Nutrition. New York: Putnam, 1987 Encarta 98 Desk Encyclopedia & 1996-97 Microsoft Corporation. Kellogg’s Crispix box. Side panel. Exp. Nov 21 1998.