Neurodivergence and dietary sugars

Neurodivergence

Neurodivergence refers to natural variations in the way the brain processes information, leading to differences in how a person behaves, learns, experiences, or reacts to the world when compared with socially defined ‘typical’ patterns. Neurodivergence is not a disorder or a formal diagnosis, and there is no universally agreed-upon list of defining features of neurodivergence.

Examples of neurodivergences include Autism Spectrum Disorder (ASD), Attention Deficit Hyperactivity Disorder (ADHD), dyslexia, dyspraxia, and Tourette’s syndrome (1). Collectively, these affect an estimated 15-20% of the global population, more than a billion people (2), with ADHD and ASD being the most studied. Genetic, biological, and environmental factors all appear to play a role in the development of neurodivergences (3).

Is there a link between diet and neurodivergence?

Some research suggests that when pregnant people get enough key vitamins and minerals, their children may have a lower risk of developing ASD or ADHD. However, these studies are observational and do not prove that diet causes or prevents neurodivergence (4, 5).

Diet and neurodivergence

Current scientific evidence does not indicate that diet has a causative role in developing neurodivergences or that changing diet can significantly influence symptoms. Most studies are observational, so they cannot determine whether diet directly affects behaviour.

Neurodivergent traits, however, may influence eating habits, which in turn can affect nutrient intakes. For example, common traits may mean some people feel anxious around food, struggle to recognise hunger or fullness, prefer certain tastes or textures, or need food to be presented in specific ways (6).

These patterns can lead to a restricted diet or limited variety. Research also shows higher rates of eating disorders – such as avoidant restrictive food intake disorder (ARFID) – among people with ASD and ADHD (7). Digestive issues and food sensitivities are also more common and can further affect what foods are tolerated or chosen.

All these factors may increase the risk of nutrient deficiencies, including those essential for brain function, cognition, and mood (8). This is supported by a recent systematic review and meta-analysis showing that children with ASD had significantly lower intakes of protein, vitamins A, B1, B2, B3, D, K, and folate (9).

Despite limited evidence supporting dietary interventions, public interest in ‘special diets’ remains high (10). These may include exclusion diets (such as gluten-free, casein-free, or ketogenic diets), or supplements (such as vitamin B6, omega-3 fats or iron). While supplements can be beneficial when prescribed to correct or prevent deficiencies (11), major health authorities do not recommend specific diets or supplements to manage or treat ASD or ADHD (6, 12, 13).

Dietary sugars and ASD

There is no scientific evidence to suggest that sugars cause ASD. Research looking for patterns between intakes of sugars and symptoms of ASD or certain behaviours is also inconclusive – while some studies report associations between higher consumption of sugars or sweetened beverages and more pronounced symptoms of ASD (14), others find no link (15).

Certain dietary approaches, such as ketogenic diets that restrict carbohydrate intake (including sugars), have been promoted to manage ASD symptoms. However, evidence for their effectiveness is limited, and these diets can lead to nutritional deficiencies. According to the UK's National Health Service (NHS), such dietary approaches are not recommended (6).

Dietary sugars and ADHD

The notion that high intakes of sugars trigger or worsen ADHD symptoms is not supported by current scientific evidence. While some observational studies suggest a potential link (16), there is no strong evidence to support the view that sugars have a causative role in ADHD or aggravate symptoms (17, 18).

Studies showing associations cannot establish whether higher intakes of sugars contribute to ADHD symptoms, result from them, or reflect another aspect of diet or lifestyle. A review of randomised controlled trials found no support for sugar elimination as a treatment for ADHD in children or teenagers (19). For more information, see Dietary Sugars and Hyperactivity.

Summary

While ASD, ADHD and other neurodivergences may affect what a person eats, there is no convincing evidence to support the idea that intakes of sugars have a role in the development of neurodivergences or affect symptoms or behaviours linked to them.

Last reviewed March 2026. Next review due March 2029.