Fiber or cellulose (sometimes called non-starch polysaccharides, NSP), offers a range of health benefits whether or not you are trying to lose weight.
Fiber is part of the carbohydrate family of foods and is so “complex” that it cannot be digested by humans.
The weight loss benefit of fiber derives from the feeling of fullness it gives without adding many calories. Fiber may also slightly reduce the absorption of fat in the gut.
The main health benefit of fiber comes from the fact that it helps to lower cholesterol, as well as speeding up digestion in the gut which is believed to reduce the risk of certain cancers.
For more information about the fiber content of foods, click Fiber