Effect of Feingold's K-P diet on a residential mentally handicapped population.

Independent investigations of Feingold's K-P diet have not produced consistent results. Even the most carefully designed experiments by Connors et al. resulted in an internal inconsistency; namely, the results differed, depending on the order in which the control and K-P diets were used. This study involved a double-blind, crossover design with random assignment to treatment and control groups. Subjects were drawn from a residential mentally handicapped population. There was no significant difference between Feingold's K-P diet and the control diet regarding the specific dependent variables of general activity, attention span, and excitability.