This systematic review asked whether the carbohydrates in a person's diet are linked to ADHD symptoms. The authors gathered 48 studies published from 2015 to 2025. Of these, 38 observed people without changing their diet, and 10 tested a diet change. Most studies involved children and teens, with fewer studies of adults.
The type of carbohydrate seemed to matter more than the total amount. The clearest pattern was for sugary foods and drinks. Among the studies that looked at added sugar, sugary drinks or sweets, 15 of 16 linked them to ADHD diagnosis or worse symptoms. Results for total carbohydrate intake were mixed. Fiber, whole grains and healthier diets tended to go with fewer symptoms, but this may reflect overall diet quality.
These links do not show cause. The authors say the findings do not support the idea that a high-carbohydrate diet causes ADHD. In one included study, ADHD symptoms predicted a poorer diet later, not the other way around.
Among the diet trials, 6 of 10 reported symptom improvement. Few of them changed only carbohydrates. In one trial of 165 children aged 5 to 12, an elimination diet worked no better than a healthy diet. Most observational studies were rated at moderate to high risk of bias.
The authors suggest diet advice could focus on limiting sugary drinks, sweets and highly refined carbohydrates in favor of fiber-rich whole foods, as added support within wider ADHD care rather than a replacement for proven treatment.
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Source: Panayotova G, Hachmeriyan A. Dietary Carbohydrates and ADHD Symptoms: A Systematic Review. Nutrients (2026). doi:10.3390/nu18101625