CELL: A cell is the basic unit of all living organisms. Some living organisms exist only as a single cell. An average-size man contains 60 to 100 trillion cells. Cells keep themselves alive, produce energy, exchange information with neighboring cells, multiply, and eventually die when their time has come. Each cell is a small container of chemicals and water wrapped up by a thin sheet of material.
TISSUE: Tissue is body material in animals and plants that’s made up of large numbers of cells that are similar in form and function.
MUSCLE: Muscles are masses of tissue in the body, often attached to bones that can tighten and relax to produce movement.
FAT: 1. Fat is naturally oily or greasy extra flesh in the body kept under the skin. Example: He had so much fat that his stomach was hanging over his beltline.
2. Fat is a substance of this type made from plant products that’s used in cooking. Some fats are important nutrients for the body to use in building cells and accomplishing other bodily activities. Example: Butter and olive oil are fats.
CALORIE: A calorie is a measurement unit of the amount of energy that can be produced by food. One calorie is enough energy to raise the temperature of one kilogram of water by one degree Celsius. Thus, when you’re referring to the calories contained in food, you’re referring to the potential energy stored in the food. Note: Extra calories taken into the body beyond what is needed to run the body or build muscle can be stored as fat.
NUTRIENT: A nutrient is a substance that gives a living body something that it needs to live and grow. Example: Water, fruits, vegetables, and meats all contain nutrients.
PROTEIN: Proteins are naturally occurring compounds that are used for growth and repair in the body and to build cells and tissues. Muscle tissue contains lots of protein. Protein keeps you strong and makes your bones last. It is an essential nutrient for life.
AMINO ACID: Amino acids are very small units of material that protein is built out of.
CARBOHYDRATE: Carbohydrates are chemical elements composed of carbon, oxygen, and hydrogen. Carbohydrates are important nutrients for energy and for building cells in the body. The word carbohydrate is formed by carbo- which means carbon, and –hydrate which means water. It is an essential nutrient for life. Example: Broccoli, lettuce, apples, bananas, bread, cereal, and sugar are all carbohydrates.
DIGESTION: Digestion is the process of breaking down food so that is can be absorbed and used by the body.
ENZYME: An enzyme is a substance produced by organisms that helps cause specific chemical reactions. Example: Certain digestive enzymes help to break down food.
METABOLISM: Metabolism is the term for the series of processes by which molecules from food are broken down to release energy, which is then used to fuel the cells in the body and to create more complex molecules used for building new cells. Metabolism is necessary for life and is how the body creates and maintains the cells that make it up.
NUTRITION: Nutrition is the process of getting nourishment, especially the process of getting food and nutrients and utilizing them to stay healthy, grow, and build and replace tissues.
SUGAR: Sugar is a class of sweet-tasting carbohydrates that come from various plants, fruits, honey, and other sources.
SUCROSE: Sucrose is the kind of sugar most commonly called “table sugar.” It is usually in the form of a white powder and is used as a sweetener. It is most often taken from natural sources but can be made artificially as well.
GLUCOSE: Glucose is a very simple sugar that is an important energy source in living things. Most carbohydrates are broken down in the body into glucose, which is the main source of fuel for all cells.
GLYCOGEN: Glycogen is a substance found in bodily tissues that acts as a store of carbohydrates.
Note: When the body has extra glucose, it stores it in the liver and muscles, and this stored form of glucose is called glycogen. Glycogen is like the body’s back-up fuel, and it releases glucose into the bloodstream when the body needs a quick energy boost. It doesn’t matter whether you eat lettuce or candy; both end up as glucose in the body. The only difference is that the lettuce takes a lot longer to break down into glucose than the sugary candy.
BLOOD SUGAR: Your blood sugar level is the amount of glucose in your blood. Glucose is carried in the blood and delivered to cells so that it can be broken down and the energy can be stored or used.
SIMPLE CARBOHYDRATE: A simple carbohydrate is a very simple form of sugar that is usually sweet tasting and is broken down into glucose very quickly. Example: Some foods that are high in simple carbohydrates are candy, white bread, dairy products, most pasta, and certain fruits.
COMPLEX CARBOHYDRATE: A complex carbohydrate is a carbohydrate that is made up of many molecules of “simple carbohydrates” linked together. Because of this, it takes the body longer to break it down into glucose. Example: Some foods that are high in complex carbohydrates are bananas, lettuce, tomatoes, oatmeal, brown rice, and beans.
STARCH: Starch is a complex carbohydrate that is found naturally in many fruits and vegetables and is sometimes added to other foods to thicken them. In its pure form it is a white powder. Starch is an important source of energy for the body. Although starch is a complex carbohydrate, some particular foods high in starch break down into glucose quickly, like a simple carbohydrate would.Example: Potatoes, corn, and bread all contain starch.
HORMONE: A hormone is a chemical made in the body that gets transported by the blood or other bodily fluids to cells and organs to cause some action or to have a specific effect. Example: Adrenaline is a hormone that is released during times of high stress or excitement that opens up the blood stream and boosts the supply of glucose and oxygen for more energy and strong, swift action.
INSULIN: Insulin is a hormone that consists of protein and is made in the organ known as the pancreas. When someone eats food, the carbohydrates are broken down into glucose, which is then absorbed into the bloodstream to be delivered to the body’s cells. When this happens, the body detects the change in blood sugar and releases insulin, which causes muscles, organs, and fat tissue to take up the glucose and either use it or store it as energy. It also causes cells to take up amino acids and build muscles.
Note: When insulin is released, the body does not use its stored fat to get energy; it only gets energy from the food that is being digested. When a person eats foods containing lots of simple carbohydrates, high amounts of insulin are released into the blood. The carbohydrates get broken down and are either used or stored as fat and glycogen very quickly, giving a boost in energy. Because all of the glucose gets broken down and stored quickly, however, the energy boost runs out very fast, and the person experiences the “crash” that comes after a sugar high.
If this is repeated on a regular basis, the insulin keeps being produced and released into the bloodstream in high amounts, bringing too much glucose to the tissues in the body. These tissues will eventually start resisting this and will refuse to accept the insulin. The extra sugar in the blood that cannot be utilized now can cause damage to the blood circulation system and ends up being stored as fat. Since the insulin is no longer helping the cells absorb glucose properly, the body is left feeling hungry, causing the person to eat even more. As this continues over a long period of time, the pancreas can get exhausted and stop producing enough insulin, causing the cells to become starved for glucose and die.
GLYCEMIC INDEX: The glycemic index (or GI) is a scale that measures the effect of different carbohydrates on one’s blood sugar level. Carbohydrates that break down slowly and release glucose into the blood slowly are low on the glycemic index. Carbohydrates that break down quickly will release glucose into the blood quickly, causing insulin levels to suddenly spike; these are high on the glycemic index. Below 55 on the GI is considered low, and above 70 is considered high. Pure glucose is 100 on the GI.
FIBER: Fibre is a substance found in some grains, fruit, and vegetables that cannot be digested. Fibre serves to soak up extra water and push other food through the digestive system. It helps push useless food waste out of the body, preventing it from sitting in the system and clogging it. Fibre is considered to play a role in the prevention of many diseases of the digestive tract. Example: Some foods containing fibre are bread, beans, bananas, onions, oats, and broccoli.
FATTY ACIDS: Fatty acids are the molecules that make up fat cells. Some fatty acids are needed for building parts of cells and tissues in the body. Fatty acids contain twice as many calories as carbohydrates and proteins and are mainly used to store energy in fat tissue. Example: Fatty acids can be found in animal fat from meat, such as beef or pork, or in oils from plants, such as olive oil.
CHOLESTEROL: Cholesterol is a soft, waxy substance found among some fats that moves through your bloodstream and into your body’s cells. Your body makes some cholesterol, and the rest comes from animal products consumed, such as meat, fish, eggs, butter, cheese, and whole milk. Cholesterol is not found in foods made from plants.
Note: One kind of cholesterol, known as “good cholesterol,” is necessary for survival and is used in building the cells in the body and for other important functions. “Bad cholesterol” can get stuck in your bloodstream and block the flow of blood, causing a heart-attack if you have too much of it in the bloodstream. SATURATED FAT : Saturated fat is a kind a fat found in some foods that tends to increase the amount of bad cholesterol in the blood. Example: Saturated fats can be found in butter, bacon, beef, and egg yolks.
UNSATURATED FAT: Unsaturated fat is a kind of fat found in food that does not raise levels of bad cholesterol, and it actually seems to lower the levels of cholesterol in the blood. It is also necessary for building cells and other body functions. Though it does have these healthy qualities, it is still a fat and has high calories, so if eaten in a large amounts, it will still make a person gain fat tissue. Example: Unsaturated fats can be found in fish oils, oils from nuts, and some vegetable oils.
TRANS FAT: Trans fat is fat that has been altered by a man-made process used to make the fat re-usable for frying things and to make foods last longer on the shelf. Trans fats have been shown to raise the level of bad cholesterol and lower the level of good cholesterol as well as lead to heart disease and some other severe diseases. Example: Trans fats can but found in many foods, especially in fried foods like French fries and donuts as well as store-bought pastries, pizza dough, cookies, and crackers.
BODY MASS INDEX (BMI): The Body Mass Index (BMI) is a scale that uses a system of numbers for estimating about how much a person should weigh depending on how tall he or she is. The BMI is meant to give a vague estimate for large groups of people or whole populations. When the BMI is used for evaluating an individual, it is very often inaccurate because of different body types, like having a thin frame, a lot of muscle tissue, or being very tall. Example: Using the BMI number system, below 18.5 is underweight, 18.5 to 25 is normal, and above 25 is overweight.