What Are The Major Purposes That Carbohydrates Serve?

Carbohydrates are one of the main types of nutrients and are the most important source of energy for the body. Our digestive system converts carbohydrates into glucose (blood sugar), which is used by the body to provide energy for the cells, tissues, and organs. The extra sugars are stored in the liver and muscles to be utilized when it is required.

Carbohydrates are classified as simple or complex, depending on their chemical structure. They also include sugars added during food processing and refining. Many of the complex carbohydrates are rich sources of fiber.1 Carbohydrates are often blamed for contributing to weight gain, but they are necessary for the optimal functioning of the body and must be part of every person’s diet. Let’s look at the major purposes of carbohydrates.


1. Major Energy Source

Carbohydrates are a major source of energy

Carbohydrates are easy to digest and provide readily available energy that is required for physical activity and for fueling all cellular and metabolic processes. Starch, sugars, and triglycerides provide the major chunk of dietary energy. To preserve homeostasis (the tendency of the body to seek and maintain a condition of balance or equilibrium within its internal environment, even when faced with external changes), most of the glucose and fat absorbed must be stored to be utilized when needed at rates appropriate to cause the oxidation of a fuel mix matching. Foods that are high in simple carbohydrates cause a sudden surge in blood glucose levels and a corresponding rapid increase in blood insulin levels.


One study found that carbohydrates increased the subjects’ feeling of energy, decreased the feeling of fatigue and improved reaction time. Carbohydrates are broken down into glucose, which is the main source of energy for human metabolism. Researchers concluded that a very low carbohydrate diet may adversely impact a person’s ability and desire to exercise.2

2. Promotes Digestion

Carbohydrates promote digestion


Normal digestion and function of the bowels largely depend on sufficient fiber intake. Fiber is also a type of complex carbohydrate that is derived from plant foods like fruits and vegetables. Soluble fiber is the pliable inner part of cell walls that contain water, derived from the soft insides of fruits and veggies. Soluble fiber binds with water in the intestines, slows down digestion and stabilizes the blood sugar levels.

Insoluble fiber is the hard part of the cell walls. Insoluble fiber is usually harder to chew and it tends to somewhat retain its shape even in the stools. Insoluble fiber improves digestion, relieves constipation and makes the stools soft. Most fibrous foods contain both varieties of fiber, but one type of fiber may be present in higher concentrations than the other.


3. Aids The Central Nervous System

Carbohydrates aid the functioning of the central nervous system

Consuming carbohydrates at regular intervals is essential for the optimal functioning of the central nervous system. The brain acts as the command center of the CNS and only uses carbohydrates for fuel. The brain, however, has no stored supply of carbohydrates and depends entirely on the glucose supply from the blood.


One specific study noted that the consumption of carbohydrate immediately before and during exercise represents an effective strategy to provide an exogenous fuel source to the muscle and central nervous system. Carbohydrates provide an additional muscle fuel source when glycogen stores become depleted, and in turn aid the performance of the central nervous system.3

4. Fuel Stockpile

Carbohydrates enable the body to store energy reserves and supply it when needed


Carbohydrates are stored in the muscles and liver in the form of glycogen and are supplied as vital reserves of energy when required. These energy reserves provide the much-needed fuel for the various processes of the body when the dietary carbohydrate is running low. But, this reserve supply of energy can last for a limited duration and can supply the body for just half-a-day. A person must consume moderate quantities of carbs throughout the day in order to maintain a normal blood glucose level and prevent the breakdown of fat and protein.

5. Rich Source Of Fiber

Carbohydrates are a rich source of fiber


Sugars and starches provide glucose, the main source of energy for the brain, central nervous system, and RBCs. Glucose also can be stored as glycogen (animal starch) in liver and muscle or, like all excess calories in the body, converted to body fat. Dietary fibers are non-digestible forms of carbohydrates. Dietary fiber, which is intrinsic and intact in plants, helps provide satiety and promotes healthy laxation. Diets high in fiber reduce the risk of coronary heart disease, diabetes, obesity, and other chronic diseases.

Role of Carbohydrates

A major role of carbohydrates is to provide energy, as they are the main source of energy for the body. Without enough carbs, the body can soon become incapable of performing physical activity, brain function, and operation of the organs. All the cells and tissues in the body require carbohydrates. Carbs are also vital for intestinal health and waste removal. Once carbohydrates enter the body, they are easily converted to energy.

Since there is an obligatory requirement for glucose in several organs such as the brain, a spontaneous increase in food intake is seen when the diet has a low-carbohydrate content. Hence, the present nutritional advice of increasing the proportion of carbohydrate energy while decreasing that of fat in the everyday diet has strong scientific support in terms of the regulation of the energy balance.4

Recommended Intake

Consuming sufficient quantities of carbohydrates each day is vital to fuel your exercise regime and everyday activities. According to the Dietary Guidelines for Americans 2010, your diet should consist of 45 to 65 percent carbohydrates. For the average 2000-calorie diet, this equals 225 to 325 grams of carbohydrates as they have 4 calories per gram. Fiber has a separate recommendation since it does not convert into glucose. You require 14 grams of fiber for every 1000 calories you have in your diet. If you follow a 2000-calorie diet, you should get 28 grams of fiber each day. For a healthy diet, limit the amount of added sugar that you eat and choose whole grains over refined grains.5

Foods Rich In Carbs

Oats, banana, orange and apple are some foods that are rich in carbs

  • Quinoa
  • Oats
  • Buckwheat
  • Banana
  • Sweet Potato
  • Beetroot
  • Orange
  • Blueberry
  • Grapefruit
  • Apple
  • Kidney Beans
  • Chickpeas
  • Yams
  • Pumpkin

Carbohydrate-Rich Foods That Diabetics Must Avoid

Diabetics must avoid processed grains, chewy fruit rolls, chocolates, regular jam and jelly

  • Processed grains, such as white rice or white flour
  • Cereals with little whole grains and lots of sugar
  • Canned vegetables with lots of added sodium
  • Veggies cooked with lots of added butter, cheese, or sauce
  • Canned fruit with heavy sugar syrup
  • Chewy fruit rolls and chocolates
  • Regular jam, jelly, and preserves (unless you have a very small portion)
  • Sweetened applesauce
  • Fruit punch, fruit drinks, fruit juice drinks