National Academies of Science definitions relating to food fibre only add confusion.

The Food and Nutrition Board (FNB) of the Institute of Medicine of the National Academy of Sciences (Washington DC, USA) recently published definitions for ‘dietary’, ‘functional’, and ‘total’ fibre (Institute of Medicine, 2002). Dietary fibre consists of non-digestible carbohydrates and lignin, which are intrinsic and intact in plants. Functional fibre consists of isolated, nondigestible carbohydrates that have beneficial physiological effects in human subjects. Total fibre is the sum of dietary fibre and functional fibre. The American Association of Cereal Chemists (AACC) is a scientific organization with a long record of being deeply involved with various aspects of research on dietary fibre, including health benefits, analytical methodology and the development, production and promotion of foods containing fibre, so it must respond to this proposed definition. A complete discussion of this topic has recently been published (DeVries, 2003)