The nutritional status of Kindergarten children has been studied in relation to performance in behavioral tests and the effects of several types of nutritional intervention in nutrition and behavior have been evaluated. In a study in 1969-70, children who received breakfast and lunch at school showed significant improvement in hemoglobin concentrations. Children who received lunch alone improved but not to an extent that was statistically significant. Children with high hemoglobin levels showed better performance in the Kahn Intelligence Test(KIT) and, in the youngest age group, in simple and disjunctive reaction time tests. Improvement in KIT occurred in children who received breakfast and lunch. In studies the next year, the nutritional status of kindergarten children was found to be better than in the previous year. Children who received breakfast and lunch did not improve significantly as compared to the control children who also improved. Children who received breakfast and lunch improved significantly in performance in the disjunctive reaction time and in continued trials of associative reaction time. Improvement was greater in subjects whose initial hemoglobin values were low. These studies indicate a relationship between mild levels of nutrient deficiency and performance tasks demanding attentiveness and alertness. (Author/JM)