Can a vegetarian or low-salt diet reduce blood pressure? men with high blood pressure are assigned at random to one of four diets: (1) normal diet with unrestricted salt; (2) vegetarian with unrestricted salt; (3) normal with restricted salt; and (4) vegetarian with restricted salt. this experiment has one factor, the type of diet. two factors, high blood pressure and type of diet. two factors, normal/vegetarian diet and unrestricted/restricted salt. three factors, men, high blood pressure, and type of diet. four factors, the four diets being compared.