Nutritional classification and analysis of food carbohydrates.

Dietary guidelines for Western countries encourage a considerable increase in carbohydrate intake. Because of new developments regarding nutritional properties of various food carbohydrates, these guidelines should include more precise recommendations of the carbohydrate composition. Small-intestinal digestibility is, nutritionally, the most important property of food carbohydrates. This was recognized early by British scientists, who differentiated between "available" and "unavailable" carbohydrates. Dietary fiber is generally defined as undigestible polysaccharides and lignin. Resistant starch is a newly discovered undigestible component included in such fiber definition, although current analysis methods do not recover all forms of resistant starch. The term "complex carbohydrates" has been used to mean digestible polysaccharides, ie, starch, in the United States, and to mean all polysaccharides, ie, both starch and nonstarch polysaccharides, in Europe. The term's usefulness is questionable because chain length of digestible carbohydrates is not related to specific nutritional advantages.