Carbohydrates are the chief source of energy for all body functions, including muscular exertion, and are necessary for the digestion and assimilation of other foods. Carbohydrates provide us with immediately available calories for energy. Free sugars, particularly glucose, are important energy fuels in the nervous system, brain, muscles, and many other tissues. Carbohydrates also help regulate protein and fat metabolism. Fats require carbohydrates to be broken down in the liver.
To understand carbohydrates, it is important to know and understand the term glycogen. Glycogen is the principal storage form of carbohydrate energy (glucose) in the body. It is stored in the muscles and in the liver. Glucose can also be formed from protein if carbohydrate levels are low. This process is called Gluconeogenesis. However, this process is not an efficient source of fuel for the muscles. Carbohydrates are the preferred fuel. This may help you understand why following a diet that is too low in carbohydrates can be harmful rather than helpful.
Carbohydrates are typically put into two categories: simple and complex. Simple carbohydrates are short chain molecules or “simple sugars.” They are broken quickly into glucose in the body. Some examples of simple sugars are fruit juice, honey and table sugar. Complex carbohydrates are longer chain molecules. They are broken down slower than the simple carbohydrates. Some examples of complex carbohydrates are potatoes, oatmeal and brown rice.
As mentioned, certain carbohydrate foods are absorbed more quickly than others and can produce a sudden rise or drop in blood glucose (blood sugar) levels. Eating evenly spaced, well balanced meals can prevent these sudden drops in blood glucose levels and even increase the rate of your metabolism.
Good sources of carbohydrates are those foods comprised of complex carbohydrates like rice, potatoes, whole grains, fruits and vegetables. Complex carbs take longer for the body to break down and burn.
How many carbohydrates do you need?
There is no specific carbohydrate requirement for humans. Carbohydrate needs will vary according to nutritional status, lean body mass, activity level, training frequency and fitness goals. In a balanced diet approximately 40-50% of your total daily calories from carbohydrates would be ideal for most people.
Up to 1/3 of your daily meals can be substituted with protein and meal replacement drinks without having a negative affect on your metabolism.