In recent years carbohydrates have been targeted as a common perpetrator for weight gain. Masked by the criticism are the necessary functions carbohydrates have in the body. Carbohydrates are defined as an essential structural component consisting of carbon, hydrogen and oxygen. The main functions carbohydrates have in the body are their role in energy supply, protein and fat metabolism, fuel reserve and proper functioning of the central nervous system.
Carbohydrates are the primary source of energy in the body. They are easy to digest and provide readily available energy that you need not only for physical activity, but for fueling all cellular and metabolic processes. Protein can be a source of energy, but it is not the body's preferred source. Fat serves as a fuel, but is needed in small quantities and is primarily serves a role with the essential fatty acids.
Regulation of Protein and Fat Metabolism
As the primary source of energy for the body, carbohydrates play a role in regulating fat and protein metabolism. With a sufficient supply of carbohydrates to meet the general needs of the body, it will not have to use protein and fat for energy. Protein will serve its primary purposes of tissue growth and repair. Fat will not be needed to supply more energy than it originally needs. This is important because excess breakdown of fat causes the production of ketones, which leads to a condition called ketosis. Ketosis causes high levels of uric acid in the blood and is associated with kidney disease, gout and heart disease.
Carbohydrate, in the form of glycogen, is stored in the muscles and liver and supplies vital reserves of energy. These reserves provide the necessary fuel for the body's overall processes when dietary carbohydrate is low. However, there is only enough energy in the glycogen reserves to supply the body for half a day. To maintain normal blood glucose levels and prevent the breakdown of fat and protein, you need to consume carbohydrates regularly throughout the day.
Central Nervous System Function
Constant consumption of carbohydrate is vital for proper functioning of the central nervous system, or CNS. The brain is the control center of the CNS and only uses carbohydrates for fuel. However, the brain has no stored supply of carbohydrate and relies solely on the glucose supply from the blood.
- "Advanced Nutrition and Human Metabolism, Third Edition;" James L. Groff and Sareen S. Gropper; 2000
- "Basic Nutrition and Diet Therapy;" Sue Rodwell Williams; 2001