ADHD and Nutrition

The impact of nutrition and diet on ADHD and child and adolescent behaviour is a widely discussed and researched topic. Aspects that have been studied include elimination diets, micronutrient supplementation, Omega-3 supplementation, the importance of breakfast, and more. Studies tend to come back with mixed results, some interventions like omega-3s have a lot of positive results, other interventions come back inconclusive. For many children and families dietary interventions can help, often significantly. For others it doesn’t make a big enough difference to be worth the cost and/or effort of sticking to the intervention. Below, I will discuss some of the dietary changes that research has shown to be most likely to support positive behavioural shifts.
Some of the most studied and most likely to make an impact nutritional shifts are simple. A healthy balanced and regular diet, omega 3 supplementation, and supplementation of micronutrients like vitamin D. I would recommend starting here for anyone who is struggling with ADHD symptoms themselves or with behavioural symptoms in their children.


If you are considering a dietary shift in your family. I would always recommend trying to stick with the change for a minimum of three weeks. The thinking on this is that it takes time for your body to adjust. If the food you are eliminating is causing inflammation in the body, it might even flare up when removed and make things feel worse for a few days before starting to improve. Change takes time. If you are adding a supplement, this also requires patience. If you are deficient in a nutrient or vitamin it will take time for the supplement to build up in your system and start to cause a shift. Be patient and take the time to see if the changes you are making to nutrition are going to have a behavioural impact.

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Let’s look at diet first. Many studies have looked at things like red dye, sugar, processed foods, and gluten. Results are inconclusive for the most part, but anecdotal evidence and some studies show that removing some or all of these items can make a difference. My take on this is like everything else I talk about on this site and in my coaching practice, everyone is unique. Every person has a unique nervous system, gut biome, and inflammatory system. If you are dealing with challenging behaviour, eliminating these widely studied items might be worth trying for your family. I personally removed these foods from my eldest daughter’s diet at age 3 and it made a significant difference for her and our family. Her eczema cleared, her gut was healthier, and her emotional regulation and behaviour improved. 

We have learned over the years that adding gluten or sugar back into her diet results in an immediate emotional and behavioural response. For our family, continuing with this diet works for us. Sometimes elimination can be scary and intimidating. Start instead by focusing on adding healthy whole foods and establishing a regular meal and snack schedule is a more positive and healthy approach. Organic foods are another great option. One study, (Bouchard 2010) showed that in a cohort of 1,100 children those with higher levels of pesticides in their urine were twice as likely to have ADHD. This does indicate that toxic exposure impacts our behaviour and ADHD and/or ADHD like symptoms. Consider incorporating organic foods when possible, and using a natural fruit/veggie wash when not possible is a simple step to help keep your diet clean. Research indicates that eating a diet that is high in protein and includes lots of organic fruits and veggies alongside healthy fats is ideal for someone with ADHD.

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Supplementation is the next step to consider. The most significant supplement to look at is Omega-3s. These fatty acids have been studied endlessly when it comes to their link to brain health, particularly ADHD brains. The importance of Omega-3s comes down to the simple fact that sixty percent of the brain is made up of fat, meaning that your brain needs a steady supply of healthy fats for it to function at its best. The building blocks of fat are called essential fatty acids. 

Two of the most important EFAs are EPA and DHA which are Omega-3s. If Omega-3 levels are low the impacts include: degeneration of the outer covering (membrane) of neurons, neurons make less serotonin, cellular receptors for dopamine are malformed, dendrites make fewer branches, and less synapses. As I outline in my blog post about ADHD and the brain, people with ADHD struggle with altered neurotransmitter levels including low serotonin and overly efficient dopamine uptake. This means that it is especially important for people with ADHD to maximise their brain health. Countless studies show that children diagnosed with ADHD often have lower blood levels of Omega-3s. Other studies indicate that low Omega-3s in children with ADHD may be genetic and that they may even struggle to metabolize fatty acids. Check out the ADDitude article linked below for more details if you are interested. But essentially Omega-3 supplementation is extremely important for brain health for all children, but in children and also adults with ADHD it is especially significant.

A second micronutrient supplement to consider in children with ADHD is vitamin D. Vitamin D has been studied and found to have an impact on a variety of neurological conditions and psychiatric diseases. When looking at ADHD, one study (Sharif 2015), compared 37, 6-12 year old children with ADHD to 37 neurotypical children. Upon blood sampling, the children with ADHD had significantly lower serum vitamin D levels. This study and others indicate that vitamin D deficiency may play a role in ADHD and ADHD symptoms. Over the past several years, the importance of the impact of vitamin D on brain development has continued to evolve. Vitamin D supplementation is actually recommended for all children, starting at birth.

In conclusion, the role of diet and supplementation when managing ADHD and ADHD like symptoms can be significant and worth considering. There are also many other dietary options, beyond the ones I mentioned today, to consider for children and adults with ADHD. This post is simply meant to highlight the most talked about and easiest to implement changes and additions that a family can make. The place to start for most families is likely the addition of omega-3 and vitamin D supplements. The second place to consider is the actual food eaten. You could start by eliminating some key foods or instead just focus on balancing and eating clean. What I would recommend though, is starting slowly and introducing changes one by one. This avoids burn out, feelings of overwhelm, and helps you to pinpoint what changes are actually making a difference.

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Bellisle F. Effects of diet on behaviour and cognition in children. Br J Nutr. 2004;92 Suppl 2:S227-S232. doi:10.1079/bjn20041171.

Bouchard, M. F., et al. “Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides.” Pediatrics, vol. 125, no. 6, 2010, doi:10.1542/peds.2009-3058.

Greenblatt, J., Greenblatt, J., & Gottlieb, B. (2020, January 27). Omega 3s: The Ultimate (ADHD) Brain Food. Retrieved September 17, 2020, from

Holton, K. F., Johnstone, J. M., Stadler, D. D., & Nigg, J. T. (2016, September 30). The Influence of Diet on ADHD. Retrieved September 17, 2020, from

Says:, C., Says:, L., Says:, K., Says:, C., Says:, L., Says:, M., . . . Says:, J. (2018, October 02). Top 10 Elimination Diet Mistakes. Retrieved September 17, 2020, from

Sharif MR, Madani M, Tabatabaei F, Tabatabaee Z. The Relationship between Serum Vitamin D Level and Attention Deficit Hyperactivity Disorder. Iran J Child Neurol. 2015;9(4):48-53.