Carbohydrates, Tryptophan, and Behavior: A Methodological Review

In this methodological review, we examine the behavioral effects of carbohydrates and tryptophan and conclude that high-carbohydrate foods do not provoke hyperactivity, contrary to popular beliefs. Unbalanced carbohydrate meals, however, often induce fatigue and can impair performance among both children and adults. Although tryptophan hastens sleep onset, dulls pain sensitivity, and may reduce aggressiveness, it is unclear whether similar effects can be obtained through carbohydrate ingestion. We provide support for the hypothesis that carbohydrates and tryptophan function similarly and like drugs that modify brain biochemistry and accompanying mood and behavior. We also examine implications for clinical populations who selectively crave carbohydrates.