Dr. Rapp is a pediatric allergist who started out skeptical but recently converted: she now sees a relationship between eating habits and some hyperactive behavior. What distinguishes her book from other writings on the subject is the moderate tone of her argument: she avoids an insistent you-are-what-you-eat attitude and admits to other sources of behavioral problems. Since 1908 observers have published papers on apparent connections between specific foods and erratic behavior in children. Milk, chocolate, and eggs are the more common offending foods along with wheat, corn, pork, peanuts, sugar, and citrus juices. Feingold has made a case against food additives, others have cited food colorings and vitamin deficiencies as culprits. Yet many physicians remain unconvinced, and Dr. Rapp does not hedge on the causes of this resistance. Many of the studies used loose testing standards; some positive results have proven unduplicable; often the definition of ""allergy"" has been stretched; and in most cases ""improvement"" involves the subjective judgment of parents and teachers. Furthermore, considerable time is required to test for each food offender and for levels of sensitivity (which may change over time). Despite these serious reservations, many children do respond to regulated diets, in combination with drugs like Ritalin and on drug-free regimens (which she prefers). Dr. Rapp does not speculate on why the incidence of food allergies appears to be rising but she does suggest general areas for further research. Parents confronted with hyperactive children will appreciate the specific tests she recommends and her cautionary approach.