Nutrition 101: Carbohydrates

Carbohydrates are the primary source of fuel the body uses for energy. From a chemical standpoint carbohydrates are made of three elements: carbon, hydrogen, and oxygen. We call these compounds saccharides and generally divide them into two basic forms – simple and complex. Mono and disaccharides - also called simple sugars are generally 6 carbon molecules. A monosaccharide is one sugar molecule. Mono= 1. A disaccharide is two sugar molecules. Di=2.
 
Glucose, galactose, and fructose are monosaccharides. Glucose is main form of carbohydrate found in the body and is important in providing energy. It can be measured in the blood (blood glucose) and stored in limited amounts. Galactose is a monosaccharide that combines with glucose to make lactose. Fructose is a monosaccharide commonly found in fruit.
 
When two monosaccharides are combined, they become a disaccharide. Glucose and fructose combine to make sucrose -- more commonly known as table sugar. When glucose and galactose combine the disaccharide lactose is created. Lactose is the natural sugar found in milk. When two glucoses combine maltose is created. Maltose is usually found when long chains of glucose are broken down.

Polysaccharides also known as complex carbohydrate are long complex links of three or more glucose molecules. Starch is a polysaccharide and the storage form of carbohydrate in plants. That is why potatoes, grains, and squash are good sources of carbohydrate.

Fiber is also a polysaccharide found in vegetables, fruits, and whole grains. The human body lacks enzymes to digest fiber, which moves through the GI tract undigested. Fiber helps lower blood glucose and reduces the risk of heart disease, and many intestinal concerns. Good sources of fiber include whole grains (yes – popcorn is a whole grain), vegetables, fruits, and legumes.

Glycogen, a polysaccharide, is the storage form of carbohydrate in the body. It consists of links of glucose molecules. Glycogen can be stored in the liver or muscles. When you aren’t eating and need fuel – the body can break down these glycogen stores to be burned for energy. Glycogen stores are limited but are restored when you eat carbohydrate containing foods.
 
The recommended amount of carbohydrate needed varies from person to person. Overall 45-65% of your calories should come from carbohydrates. When eating carbohydrates some choices are healthier than others. Whole grains, fruits, vegetables, grains, legumes, and low-fat milk not only provide carbohydrates but are packed with vitamins and minerals and all the above choices (except milk) give you a good dose of fiber. Soda, pastries, honey, sugar, and candy also provide carbohydrate, but are low in vitamins, minerals, and fiber and should be limited for a healthy diet. A healthy eating pattern includes filling your plate with healthy carbohydrate containing foods. Half your plate should be fruits and vegetables and one-fourth grains.