Total daily caloric requirement for carbohydrates
In the previous article (Part 1 of this series), carbohydrates was specifically mentioned as the most immediate source of energy because it is easily burned and used by the cells of the human body. Thus, for active individuals and for those who do physical exercises, it was suggested that seventy percent (70%) of the total daily caloric requirement (TDCR) must be derived from carbohydrates.
General uses of carbohydrates in the human body
- Source of energy
In Diagram 1, it is shown that before carbohydrates can be used by the cells of the human body, they must be converted first to glucose. When an individual takes in adequate amount of carbohydrates, the glucose that enters the cells are either used directly for energy or stored in the liver and skeletal muscles in the form of glycogen. In the future, when the same individual suddenly finds himself in need of extra energy, this glycogen will be broken down into glucose which can then be used as emergency source of energy. When too much carbohydrates is taken in, however, such that the excess amount cannot be used by, or stored in, the body, it will be converted to fats in the form of adipose tissue.
- Antiketogenic effect
When an individual takes in inadequate amount of carbohydrates, the body will look for other sources of energy. The next in line as possible source of energy after carbohydrates will be the fats. Fats will be processed, and energy will be derived from them! However, in emergency situation wherein fats are used as source of energy, their burning is not complete, and it will lead to the production of acids known as ketones. When ketones are produced in significant amount, they accumulate in the blood, and will lead to ketoacidosis—an emergency situation wherein the acid-base balance in the system of an individual is greatly disrupted causing the affected individual to become comatose! If adequate amount of carbohydrates could have been taken, this emergency situation could have been prevented, and this is called the antiketogenic effect of carbohydrates.
- Protein-sparing action
When the intake of carbohydrates is very much restricted, such that even fats have been exhausted, the next in line as possible source of energy will be the proteins. Thus, proteins will be burned, and they will be used as source of energy! In fact, in severe lack of carbohydrates, such as in cases of malnutrition, the muscles, which are made up of proteins, will be used by the body as source of energy! Thus, children and adults whose muscles are used for this purpose are emaciated, and their muscles are significantly gone, known as muscle wasting. In situation wherein proteins are used as source of energy, building and repairing tissues which are their primary functions will be sidelined and neglected! If adequate amount of carbohydrates was taken in by this individual, proteinscould have been spared as source of energy! This is called the protein-sparing action of carbohydrates.
From the foregoing, it is clear that if you are actively engaged in physical exercises that you need to follow your TDCR for carbohydrates. If you take more than what you need, you will gain weight, and you will store fats in your body. If you take less than what you need, you will lose weight—probably less than your ideal body weight—and you might even end up suffering from ketoacidosis, especially if you are a diabetic.
- Roth, Ruth A. Nutrition and Diet Therapy. Singapore: Delmar Learning, 2007.
- Castro, Jose S. “Practical insights on how to stay fit: Proper and adequate diet (3rd of a series)”. Lifelink March 2000: 30-31.