Fiber, carbohydrates found in plants, are divided into two categories: soluble, those that dissolve in water and insoluble, those that cross the digestive tract and are eliminated almost intact.
Daily consumption of soluble and insoluble fiber brings important health benefits: it helps control weight, optimizes digestion and prevents constipation.
Soluble fiber also helps to lower the level of cholesterol and blood glucose level. Insoluble fiber is recommended in some weight loss diets, because it maintains the feeling of satiety for longer.
Some studies suggest that an increased intake of dietary fiber in the diet could reduce the risk of death from cardiovascular disease and cancer. (MedLine Plus / Dietary fiber) (Mayo Clinic/ Nutrition and healthy eating/ Dietary Fiber: Essential for a Healthy Diet)