A large group of hyperactive children whose regular diets included food containing large amounts of additives was observed by researchers trained to assess the presence or absence of behavior problems  The children were then placed on a low-additive diet for several weeks, after which they were observed again  Originally nearly 60 percent of the children exhibited behavior problems; after the change in diet, only 30 percent did so
On the basis of these data, it can be concluded that food additives can contribute to behavior problems in hyperactive children
exactly how many children exhibited behavior problems after the change in diet cannot be determined, since the size of the group studied is not precisely given