The National Advisory Committee on Hyperkinesis and Food Additives reviewed all the research and concluded there was no evidence that hyperactivity was associated with specific food additives. But they also stated there was no reason to discourage families who wish to use the diet. In fact, the diet may work for some children but not because of the food additives. There are a number of reasons why the diet may seem to calm some children. One reason is that foods that are banned by the diet because they include additives known as salicylates also have high amounts of sugar.
Salicylates are common in foods like candy, pies, soft drinks, and sweet rolls.
If you eliminate those foods, you're eliminating a lot of sugar. Another factor is psychological expectation. If a parent thinks the special diet will solve the problem, then he or she is likely to look for positive changes in the child and believe the diet is responsible. The Feingold Diet also is strict. It's difficult for many families to stay on it.