Does Sugar Affect Student Behavior or Achievement?

Why is this question important? A common wisdom of American culture is that consuming sugar has an adverse effect on behavior, especially the conduct of children. Ask any group of parents and you are likely to hear stories of agitated or uncontrollable episodes after a child has gone through a bag of candy. Thus an important question for parents as well as teachers is, does sugar actually increase inappropriate behavior and/or decrease a child's ability to learn?

See further discussion below.


Source(s): The Effect of Sugar on Behavior or Cognition in Children: A Meta-Analysis

Result(s): The conclusion of the meta-analysis was that sugar did not affect the behavior of children or the cognitive functioning of children. It found a small to medium positive effect size for sugar consumption and academic achievement. The study did not have sufficient data to rule out the possibility that sugar could have an effect on subsets of the population.

Implication(s): There are two important implications from this study: (1) Parents and teachers should have little concern that a diet including sugar will impede learning or increase instances of disruptive behavior. (2) It is important to recognize that a majority of the population can hold a belief that is not evidence based. Examining the data is crucial.

Author(s): Mark L. Wolraich, David B. Wilson, and J. Wade White

Publisher(s): Journal Of the American Medical Association (JAMA)

Study Description: The study is a meta-analysis of the available research derived from a literature review of Medline and PsychINFO. Of the 23 studies, 16 met the following criteria for inclusion in the meta-analysis:

  1. The study's design required subjects to consume sugar.
  2. The design included the use of a placebo such as an artificial sweetener.
  3. The subjects, parents, and researchers were blind to the conditions.
  4. The study reported data that could be used to compute effect sizes.


  1. Actometer: An instrument to measure movement and activity.
  2. Continuous performance test: A measure of a person's sustained and selective attention and impulsiveness.
  3. Neuro-psychological test: A scientifically validated objective test to evaluate brain functions.
  4. Paired associate learning: A test that involves the pairing of two items, usually words, consisting of a stimulus and a response. For example, words such as "calendar" (stimulus) and "shoe" (response) may be paired, and when the learner is prompted with the stimulus, he or she responds with the appropriate word ("shoe").

Citation: Wolraich, M. L., Wilson, D. B., & White, J. W. (1995). The effect of sugar on behavior or cognition in children. JAMA: The Journal of the American Medical Association, 274(20), 1617-1621.