THE USE OF FUZZY-LOGIC IN NUTRITION

Fuzzy logic is a mathematical approach to deal with systems that can n ot be defined precisely. Nutrient requirements fall into this category . Dietary intakes of nutrients are such that if a nutrient is given in graded amounts, with all other nutrients constant, there is no defini tive border where, for example, one intake is deficient and another, s lightly higher intake, adequate. Thus, fuzzy sets were developed that describe the range of intakes of a nutrient, ranging from deficiency t o excess. On the basis of these fuzzy sets and the known nutrient comp osition of the food, an index is derived that reflects how closely the diet of an individual meets all the nutrient requirements set by the German Society of Nutrition. Because this is a computer-based system, alterations in the diet are suggested if the diet does not meet requir ements. The suggested dietary alterations are usually small but nevert heless allow the diet to meet recommendations. It is important that th e suggested alterations be small because the fewer the suggested chang es in a diet, the greater the chance a person will accept the changes. Thus nutrient intake can be described and evaluated by using fuzzy de cision making. This has present applicability in nutrition education a nd could possibly be used as a tool in determining recommended dietary allowances.