Hyperactivity and dietary sugars

This content is authored by Registered Dietitian, Juliette Kellow.

Hyperactivity

Hyperactivity is characterised by excessive motor activity (1) that typically manifests in behaviours such as excessive movement or talking, constant fidgeting, difficulty sitting still, or being unable to concentrate on tasks (2). While commonly experienced by children, adults may also display hyperactive behaviour.

Causes of hyperactivity

Hyperactivity may be linked to certain physical or mental health conditions. For example, it can be a symptom of an overactive thyroid (hyperthyroidism) (3) and is a common symptom of Attention Deficit Hyperactivity Disorder (ADHD) (4). However, there is often no recognised medical cause. Instead, hyperactive behaviour may result from being excited, overstimulated or in an energetic or boisterous environment such as a children’s party or play get-together.

Is hyperactive behaviour caused by dietary sugars?

The short answer is no. Scientific research has categorically discredited the myth that sugars cause behavioural changes such as hyperactivity (5, 6, 7, 8). Nevertheless, the idea remains ingrained in popular culture with many people, including parents and teachers, still believing that consuming foods or drinks containing high amounts of sugars affects behaviour and causes children to become hyperactive (9).

The myth seems to have grown from a few small, poorly-designed studies carried out over 45 years ago that suggested sugars may be linked to hyperactivity (10, 11), although they were unable to prove that sugar was the cause. These early studies set the ball in motion for more robust and extensive investigations, which went on to establish that sugars have no adverse effects on behaviour and do not lead to hyperactivity. This research includes a meta-analysis, which combined the results of 16 well-designed studies (5). The latter concluded that sugars do not affect children’s behaviour or cognitive performance, and suggested parents’ strong belief in a link may be due to expectancy and common association.

Research confirms that adults often ‘expect’ children to become ‘hyperactive’ after consuming sweets or other foods and drinks high in sugars. In one small study, mothers who described their children to be ‘sensitive to sugars’ were told they had consumed sugars even when they had not. Those mothers went on to report higher levels of hyperactive behaviour in their children, compared to a similar control group, despite them having no actual sugars (12).

The expectation and belief that sugars cause hyperactivity serve to reinforce the myth. If parents or teachers anticipate a behavioural change after consuming foods or drinks high in sugars, they may be more likely to interpret excited, lively, or energetic behaviour as hyperactivity. Furthermore, when adults believe two things are linked – such as high intakes of sugars and negative behaviours – they may be more likely to notice and remember times when both happen together, and to forget those times when they did not (13).

It also means other environmental influences or stimulating situations that affect behaviour and activity levels – such as parties, holidays, play dates, and screen use – may be overlooked, especially as they often coincide with a greater consumption of sugary foods and drinks. This further perpetuates the myth that sugars are responsible for hyperactive behaviour, when in fact, other factors are more likely responsible (13).

Do sugars have a role in ADHD?

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental difference that affects a person’s ability to focus, manage their impulses and regulate their activity levels, often making daily life more challenging. Although the exact causes aren’t fully understood, research increasingly shows that both genetics and environmental factors play a role in its development (14). Globally, it is estimated to affect up to 3% of pre-school children, up to 8% of children and adolescents, and up to 7% of adults (15). Medication, therapy, and education can help manage symptoms (16).

Some people have suggested that diet, including high intakes of sugars, might affect the development of ADHD or its symptoms, but research does not support this.

While some observational studies suggest a link (17), there is no strong evidence that sugars have a causative role in ADHD or heighten ADHD symptoms and behaviours (18, 19). In short, studies that show an association are unable to determine whether higher intakes of sugars contribute to ADHD symptoms or are in response to them, or whether it is a related aspect of diet or lifestyle that is affecting symptoms. Meanwhile, a review of randomised controlled trials investigating dietary interventions to treat ADHD in children and teens found none in favour of eliminating sugars (20). For more information, see the article on neurodivergences.

Summary

Despite the widespread belief that sugars cause hyperactivity or behavioural changes, especially in children, there is no scientific evidence to support this in those with or without ADHD.

References

1. NICE. Attention Deficit Hyperactivity Disorder: What is it? Available at: https://cks.nice.org.uk/topics/attention-deficit-hyperactivity-disorder/background-information/definition/

2. NHS Nottinghamshire Healthcare. Hyperactivity and Impulsivity. Available at: https://www.nottinghamshirehealthcare.nhs.uk/ness-hyperactivity-and-impulsivity/

3. NHS. Symptoms – Overactive Thyroid (Hyperthyroidism). Available at: https://www.nhs.uk/conditions/overactive-thyroid-hyperthyroidism/symptoms/

4. NHS. ADHD in children and young people. Available at: https://www.nhs.uk/conditions/adhd-children-teenagers/

5. Wolraich ML, et al. The effect of sugar on behavior or cognition in children. A meta-analysis. JAMA. 1995;274(20):1617-21.

6. Wiles NJ, et al. 'Junk food' diet and childhood behavioural problems: results from the ALSPAC cohort. Eur J Clin Nutr. 2009;63(4):491-8.

7. Benton D. Sucrose and behavioral problems. Crit Rev Food Sci Nutr. 2008;48(5):385-401.

8. Wolraich ML, et al. Effects of diets high in sucrose or aspartame on the behavior and cognitive performance of children. N Engl J Med. 1994;330(5):301-7.

9. DiBattista D, Shepherd ML. Primary school teachers' beliefs and advice to parents concerning sugar consumption and activity in children. Psychol Rep. 1993;72(1):47-55.

10. Bellisle F. Effects of diet on behaviour and cognition in children. Br J Nutr. 2004;92 Suppl 2:S227-32.

11. Prinz RJ, et al. Dietary correlates of hyperactive behavior in children. J Consult Clin Psychol. 1980;48(6):760-9.

12. Hoover DW, Milich R. Effects of sugar ingestion expectancies on mother-child interactions. J Abnorm Child Psychol. 1994;22(4):501-15.

13. Flora SR, Polenick CA. Effects of sugar consumption on human behavior and performance. Psychol Rec. 2013;63(3):513–24.

14. Rhode LA, et al (Editors). The World Federation of ADHD Guide. 2019. Available at: https://www.adhd-federation.org/_Resources/Persistent/6d9ca34c09972aea00d0ea6d02be6f6d6bd5bb4c/The%20WF%20ADHD%20Guide_072019.pdf

15. ADHD Institute. Burden of ADHD. Date of preparation: July 2025. Available at: https://adhd-institute.com/burden-of-adhd

16. ADHD Institute. Disease Management. Date of preparation: July 2025. Available at: https://adhd-institute.com/disease-management

17. Farsad-Naeimi A, et al. Sugar consumption, sugar sweetened beverages and Attention Deficit Hyperactivity Disorder: A systematic review and meta-analysis. Complement Ther Med. 2020;53:102512.

18. Del-Ponte B, et al. Dietary patterns and attention deficit/hyperactivity disorder (ADHD): A systematic review and meta-analysis. J Affect Disord. 2019;252:160-173.

19. Del-Ponte B, et al. Sugar consumption and attention-deficit/hyperactivity disorder (ADHD): A birth cohort study. J Affect Disord. 2019;243:290-296.

20. Uldall Torp NM, Thomsen PH. The use of diet interventions to treat symptoms of ADHD in children and adolescents - a systematic review of randomized controlled trials. Nord J Psychiatry. 2020;74(8):558-568.