Wikipedia (an online encyclopedia) defines carbohydrates as this: "chemical compounds that act as the primary biological means of storing or consuming energy, other forms being fat and protein. Relatively complex carbohydrates are known as polysaccharides. Carbohydrates are naturally produced by plants. A more precise definition of carbohydrates is: carbohydrates are polyhydroxyaldehydes, or polyhydroxyketones and their derivatives."

The simplest way to put this into layman's terms is to say that carbohydrates are naturally occurring sugars that your body transforms into energy (you know the stuff that helps you move when the alarm clock goes of every morning). Carbs come in two categories Simple, and Complex. Simple carbs contain between 1-3 units of sugar linked to a single molecule, while complex carbs contain hundreds or thousands of sugar units attached to a single molecule. The easiest way to tell the difference is that simple carbohydrates taste sweet, complex carbohydrates are pleasant tasting but not sweet.

Within complex carbs there are two subcategories; high fiber and low fiber. Human beings cannot digest high fiber carbs. Grass for example is a high fiber complex carb; cows can digest it, but humans receive no caloric intake from eating it. The reason humans cannot digest high fiber carbs is due to "cellulose".

"High-fiber (high-cellulose) vegetable foods are the healthiest choices for human nutrition, and intake of these foods is associated with lowered incidences of hypertension, cancer, arthritis, diabetes, etc. Examples are lettuce and broccoli. Examples of low-fiber, complex carbs are banana, tomato, squash and all cereals and grains (therefore bread and pasta), potatoes and rice. Carbohydrates in Nutrition by Ron Kennedy, M.D., Santa Rosa, California"

How does all this information about carbohydrates relate to dieting? It is simple- don't eat more than you burn. If you eat a large amount of low fiber complex carbs you are filling your body with a ton of energy, which if you don't use will be converted to sugar and stored as fat. If you are an athlete it might be a good idea to eat a large plate of spaghetti the night before and event. If you only intend to spend the next day sitting around at a desk, you should make that a small plate of spaghetti.

The idea behind no carb diets is that if you eat foods high in protein you will still get the energy you need with out all the sugar.

"Strictly speaking, carbohydrates are not necessary for human nutrition because proteins can be converted to carbohydrates-the traditional diet of some peoples consists of nearly zero percent carbohydrate, and they are perfectly healthy. However, carbohydrates require less water to digest than proteins or fats, and are an important source of energy.

Low-carbohydrate diets such as the Atkins Nutritional Approach advocate the restriction of carbohydrate consumption as a means to achieving weight loss or overall good health.

Problems have been cited for the long term effects of a no-carbohydrate diet. These include reduced athletic performance, possible brain damage, and nephrotoxicity. The brain can only utilize carbohydrates for energy, and protein may not supply enough in many cases. The increase in protein means that more ammonia groups need to be removed from the blood. http://en.wikipedia.org/wiki/Carbohydrate"

On the flip side diets that are too high in carbohydrates

"…also cause generalized vascular disease. The high-carbohydrate diet which is now so popular causes the pancreas to produce large amounts of insulin, and if this happens for many years in a genetically predisposed person, the insulin receptors throughout the body become resistant to insulin. Because insulin's action is to drive glucose into the cells, this results in chronic hyperglycemia, also called "high blood sugar." A large portion of this sugar is stored as fat resulting in obesity. Excess insulin also causes hypertension and helps initiate the sequence of events in the arterial wall which leads to atherosclerosis and heart disease Carbohydrates in Nutrition by Ron Kennedy, M.D., Santa Rosa, California."

It seems that what your mother has been telling you for years - eat your vegetables and go play outside- is sound advice!

Good Simple Carbohydrate Foods

• Apples
• Blackberries
• Cherries
• Grapefruit
• Kiwi
• Lemon
• Melons
• Oranges
• Peach
• Pear
• Plum
• Raspberries
• Strawberries

Good Complex Carbohydrate Foods

• Brown Rice
• Oats
• Whole Wheat Pasta
• Beans
• Lettuce
• Spinach
• Broccoli
• Cauliflower
• Mushroom
• Cabbage
• Sprouts

They key to a healthy carbohydrate diet is to eat foods that have the lowest amount of sugars, but pack the highest amount of vitamins and other nutrients.

Great Online Resources for More Info.

Your Diet

The Center for Young Women's Health, Children's Hospital Boston

Lowcarbezine!