Cellulose is a thick, strong fiber that that gives vegetables and fruits their structural integrity. It is one type of dietary fiber that can be eaten but is not digested. Almost all the fruits and vegetables are rich sources of cellulose.
When eaten, cellulose passes through the gastrointestinal tract relatively intact. It is insoluble, meaning it does not dissolve in water.
It acts a sweeping mop for your intestines by encouraging the movement of food through them, thus helping to prevent constipation and irregularity.
There is also evidence to suggest a correlation between a high-cellulose diet and a low risk of colon cancer.
Although fiber is a type of carbohydrate but it earns a separate place along with other macronutrients such as Proteins, Fats and Carbohydrates.