Does sugar really make children hyperactive?

No good evidence shows that sugar makes children hyperactive. Randomized, blinded trials have repeatedly failed to find differences in behavior between children given sugar and children given a placebo. The belief is widespread among parents, but it is generally treated by pediatric and nutrition bodies as a myth. A few sources leave room for small or subgroup effects, which is covered below. [1] [2]

A 1995 meta-analysis in JAMA by Wolraich, Wilson and White pooled 23 within-subject studies from 16 reports. For each of 14 measures of behavior or thinking, the confidence interval for the average effect included zero, and the authors concluded that sugar does not affect children's behavior or cognitive performance. They added that a small effect, or effects on subsets of children, could not be ruled out. [3]

A 2008 BMJ feature reported at least 12 double-blind randomized trials of diets with different sugar levels. None, including those focused on children with ADHD, detected behavioral differences. The American Academy of Pediatrics' parent site describes a study in which boys said to be sugar reactive were less active after a large dose of sugar. It also notes that children with ADHD respond to sugar in blood glucose tests just as other children do. [1] [2]

Studies have found that when parents are told their child had a sugary drink, they rate the child as more hyperactive, even when the drink was actually sugar-free. The JAMA authors attribute parents' strong belief to expectancy and common association. Snopes adds that confirmation bias may play a part, since a parent expecting wildness notices it more. [1] [4] [3] [5]

Context matters too. Children tend to eat sweets at birthdays, holidays and parties, where friends, games and gifts raise excitement. The American Academy of Pediatrics suggests the event may matter more than the sugar. The Academy of Nutrition and Dietetics says the idea traces back to a single mid-1970s case in which one child's behavior improved after sugar was removed. [5] [2] [4]

Most of the sources above hold that sugar has no behavioral effect. The Academy of Nutrition and Dietetics page notes that some studies suggest children with ADHD may be more sensitive to sugar, which conflicts with the BMJ and AAP reports of no differences in ADHD studies. The JAMA authors also did not exclude a small effect in some children. MedlinePlus says refined sugars cause rapid blood sugar changes that may make a child more active, and says other experts disagree. It also calls the link between artificial colorings and hyperactivity undecided. The AAP calls evidence for dyes weak and not widely accepted, and Snopes quotes Michael Kramer saying the food additive theory was effectively disproven by randomized trials. The results here do not settle the dye question, and the most widely cited reviews favor no sugar effect. [4] [1] [3] [6] [2] [5]