Chapter 1: Choosing What You Eat and Why

Gastrointestinal Tract

The main sites in the body used for digestion and the absorption of nutrients. It consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Also called the digestive tract.

Triglyceride

The major form of lipid in the body and in food. It is composed of three fatty acids bonded to glycerol.

Hunger

The primarily physiological (internal) drive to find and eat food, mostly regulated by internal cues to eating.

Appetite

The primarily psychological (external) influences that encourage us to find and eat food, often in the absence of obvious hunger.

Nutrition

The science that links foods to health and disease. It includes the processes by which the human organism ingests, digests, absorbs, transports, and excretes food substances.

Cell

The structural basis of plant and animal organization. Contain genetic material and systems for synthesizing energy-yielding compounds. They have the ability to take up compounds from and excrete compounds into their surroundings.

Water

The universal solvent, chemically H20. The body is composed of 60% water. Water (fluid) needs are about 9 (women) or 13 (men) cups per day; needs are greater if one exercises heavily.

Cardiovascular Disease

A general term that refers to any disease of the heart and circulatory system. This disease is generally characterized by the deposition of fatty materials in the blood vessels (hardening of the arteries), which in turn can lead to organ damage and death. Also termed coronary heart disease (CHD), as the vessels of the heart are the primary sites of the disease.

Compound

A group of different atoms bonded together in definite proportion.

Diabetes

A group of diseases characterized by high blood glucose. Type 1 diabetes involves insufficient or no release of the hormone insulin by the pancreas and therefore requires daily insulin therapy. Type 2 diabetes results from either insufficient release of insulin or general inability of insulin to act on certain body cells, such as muscle cells. Persons with type 2 diabetes may or may not require insulin therapy.

Bond

A linkage between two atoms formed by the sharing of electrons, or attractions.

Solvent

A liquid substance in which other substances dissolve.

Macronutrient

A nutrient needed in gram quantities in a diet.

Micronutrient

A nutrient needed in milligram or microgram quantities in a diet.

Glucose

A six-carbon sugar that exists in a ring form; found as such in blood, and in table sugar bound to fructose; also known as dextrose, it is one of the simple sugars.

Genes

A specific segment on a chromosome. They provide the blueprints for the production of all body proteins.

Element

A substance that cannot be separated into simpler substances by chemical processes. Common elements in nutrition include carbon, hydrogen, nitrogen, calcium, phosphorus, and iron.

Essential Nutrient

A substance that, when left out of a diet, leads to signs of poor health. The body either cannot produce this nutrient or cannot produce enough of it to meet its needs. Then, if added back to a diet before permanent damage occurs, the affected aspects of health are restored.

Risk Factor

A term used frequently when discussing the factors contributing to the development of a disease. A risk factor is an aspect of our lives - such as heredity, lifestyle choices (e. g. smoking), or nutritional habits.

Cholesterol

A waxy lipid found in all body cells. It has a structure containing multiple chemical rings that is found only in foods that contain animal products.

Phytochemical

A chemical found in plants. Some may contribute to a reduced risk of cancer or cardiovascular disease in people who consume them regularly.

Carbohydrate

A compound containing carbon, hydrogen, and oxygen atoms. Most are known as sugars, starches, and fibers.

Lipid

A compound containing much carbon and hydrogen, little oxygen, and sometimes other atoms. They do not dissolve in water, and include fats, oils, and cholesterol.

Hormone

A compound secreted into the bloodstream by one type of cell that acts to control the function of another type of cell. For example, certain cells in the pancreas produce insulin, which in turn acts on muscle and other types of cells to promote uptake of nutrients from the blood.

Enzyme

A compound that speeds the rate of a chemical reaction but is not altered by the reaction. Almost all are proteins (some are made of genetic material).

Obesity

A condition characterized by excess body fat.

Cancer

A condition characterized by uncontrolled growth of abnormal cells.

Hypertension

A condition in which blood pressure remains persistently elevated. Obesity, inactivity, alcohol intake, excess salt intake, and genetics may each contribute to the problem.

Stroke

A decrease or loss in blood flow to the brain that results from a blood clot or other change in arteries in the brain. This in turn causes the death of brain tissue. Also called a cerebrovascular accident.

Chemical Reaction

An interaction between two chemicals that changes both chemicals.

Inorganic

Any substance lacking carbon atoms bonded to hydrogen atoms in the chemical structure.

Organic

Any substance that contains carbon atoms bonded to hydrogen atoms in the chemical structure.

Nutrients

Chemical substances in food that contribute to health, many of which are essential parts of a diet. They nourish us by providing calories to fulfill energy needs, materials for building body parts, and factors to regulate necessary chemical processes in the body.

Complex Carbohydrate

Carbohydrate composed of many monosaccharide molecules. Examples include glycogen, starch, and fiber.

Metabolism

Chemical processes in the body by which energy is provided in useful forms and vital activities are sustained.

Polysaccharide

Class of complex carbohydrates containing many glucose units, from 10 to 1,000 or more.

Disaccharide

Class of sugars formed by the chemical bonding of two monosaccharides.

Vitamin

Compound needed in very small amounts in the diet to help regulate and support chemical reactions in the body.

Salt

Compound of sodium and chloride in a 40:60 ratio.

Osteoporosis

Decreased bone mass related to the effects of aging, genetic background, and poor diet in both genders, and hormonal changes at menopause in women.

Mineral

Element used to promote chemical reactions and to form body structures.

Alcohol

Ethyl alcohol or ethanol (CH3CH2OH) is the compound in alcoholic beverages.

Protein

Food and body compounds made of amino acids. Contain carbon, hydrogen, oxygen, nitrogen, and sometimes other atoms in a specific configuration. Contain the form of nitrogen most easily used by the body.

Kilocalorie (kcal)

Heat energy needed to raise the temperature of 1,000 grams (1L) of water to 1 degree Celsius; also written as Calories.

Chronic

Long-standing, developing over time. When referring to disease, this term indicates that the disease process, once developed, is slow and lasting. A good example is cardiovascular disease.

Fatty Acid

Major part of most lipids; primarily composed of a chain of carbons flanked by hydrogen.

Simple Sugar

Monosaccharide or disaccharide in the diet.

Monosaccharide

Simple sugar, such as glucose, that is not broken down further during digestion.

Atom

Smallest combining unit of an element, such as iron or calcium. Consist of protons, neutrons, and electrons.

Satiety

State in which there is no longer a desire to eat; a feeling of satisfaction.

Fiber

Substances in plant foods not digested by the processes that take place in the human stomach or small intestine. Adds bulk to feces. Fiber naturally found in food is also called dietary fiber.

Electrolytes

Substances that separate into ions in water and, in turn, are able to conduct an electrical current. These include sodium, chloride, and potassium.

Amino Acid

The building block for proteins containing a central carbon atom with nitrogen and other atoms attached.