Conventional wisdom has it that giving young children chocolate will cause them to become fidgety. This belief is so pervasive that many parents won’t give their kids candy within several hours of bedtime, convinced their children won’t be able to sleep. After Halloween, many parents ration their kids’ candy consumption, again based at least partly on the belief that too much candy will cause kids to go bonkers.
But when Michelle Ingram and Ronald Rapee became interested in the phenomenon, they were surprised to find that in fact very little research has been done on the effect of chocolate on children’s behavior. While several studies have found very small behavioral effects of artificial flavoring and coloring, the limited research on sugar consumption has found no effects. Some studies have found that exposing children to large quantities of caffeine does affect behavior, but the amounts involved substantially exceed what is found in a typical candy bar.
Despite this lack of evidence, when Ingram and Rapee approached five preschools to ask them to participate in a study of the effects of chocolate on behavior, two schools turned them down because they were certain that the chocolate would adversely affect the kids. Nonetheless, they persisted, and the resulting study of 26 four-year-old preschoolers is the largest study of the effect of chocolate on children.
The study design was simple: the experimenters videotaped children while they were being read a seven-minute-long story. Then the children were fed a snack of either three Freddo Frogs (the most popular children’s chocolate in Australia) or the equivalent weight of dried fruit (45 grams — roughly equal to a typical 1.5-ounce American candy bar). All the kids in each class ate the same snack. This was a lot of chocolate for these kids: in most cases, the experimenters had to coax the children to eat the third frog. Then, after playing for 30 minutes, the children were read another seven-minute story. One week later, each class got to repeat the experiment with the other type of food, so every child had one chocolate snack and one fruit snack, and heard four different seven-minute stories.
Each child’s behavior was then rated by trained observers who were unaware of the study conditions. Here are the results:
Ratings were broken into two categories: objective, which measures specific actions such as getting up, fidgeting, talking, etc., and subjective, where the observers rated each child on a subjective scale for the overall levels of movement and concentration. As you can see, there was no difference between the subjective ratings for behavior before or after eating chocolate or fruit. The slight increases in objective behavior measures were not significant. The only significant difference, in fact, was that overall on fruit days, the objective measures showed more activity and less concentration compared to the chocolate days.
This suggests that other phenomena such as weather, other goings-on in the classroom, and so on, are much more likely to affect behavior than the particular food a child eats. There is no evidence to suggest that eating chocolate significantly affects preschoolers’ behavior. Unfortunately, the study has little to say about what happens when your 12-year-old consumes six pounds of candy after trick-or-treating for four hours.
Ingram, M., & Rapee, R.M. (2006). The effect of chocolate on the behaviour of preschool children. Behaviour Change, 23(1), 73-81.