[Evaluation of nutrient intake using fuzzy sets]. 
Fuzzy sets are especially suitable to evaluate the intake of a nutrient.  For the evaluation of several components, the harmonic mean of the individual fuzzy values proves to be the best compromise.  The mean of all nutrients results in the so called Prerow value, which can be used for the evaluation of the nutrition status.  Maximizing the Prerow value is suitable for optimizing nutrition.