Carbohydrates are macronutrients found in the diet that are used for the production of energy. They include simple sugars such as those found in fruits or processed foods like jams, and complex sugars such as starch found in cereals and some vegetables.  They are important in the human body as they form the major bulk of energy substrates.

Once ingested, the complex carbohydrates are broken further to simpler classes which are further broken down and used for energy and the constant running of the body. As a source of energy, they are used for thermogenesis and the maintenance of the normal body temperature. Excess carbohydrates are stored in the liver as glycogen. The human body is however able to produce energy from fat and protein in cases where there in inadequate intake of carbohydrates.

Apart from production of energy, carbohydrates, especially complex ones such as cellulose, are needed in the body for smooth bowel hygiene. Cellulose got from plant cell walls is also known as fiber. It is indigestible and acts only as a bulk forming agent in stool. It adds bulk to stool therefore stretching the intestinal walls. As a result, there is propulsion of bowel contents forwards. The end result is freedom from constipation.

With the advent of the multitude of processed food, it became clear that there exists good and bad carbohydrate. The bad carbohydrates are usually considered the simple sugars found in processed foods that have a high caloric content and sodium and low in fiber and nutrients. They have been shown to increase the risk for development of diabetes as they have a high glycemic index.  On the other hand, good carbohydrates are usually from natural sources such as vegetables and grains. They consist mostly of complex carbohydrates and are high in nutrient content, have a low glycemic index, low sodium and cholesterol content with high fiber content.

These macronutrients are known to be very important for the mental wellbeing of oneself.  With inadequate intake, there is no substrate for the production of glucose needed for the functioning of the nerves. There develops lethargy and finally loss of consciousness in extreme cases.  The energy is also needed to sustain muscle use and to prevent catabolism of proteins in the body to produce energy.

It is safe to say that carbohydrates are necessary for human bodies and moderation in intake should be limited to processed ones.