ASK THE NUTRITIONIST: How does nutrition affect a child’s behavior?

Andara Puchino

For a healthy diet to succeed long term, it needs to not be perceived as a restriction but as a new way of life

In her weekly column, licensed nutritionist Nonie De Long shares foods known to trigger hyperactivity and mood problems in kids …

Dear Readers,

This week’s column comes from a question I received from Dale in Toronto. He reached out to better understand the link between food and behaviour in children, as his son was having troubles in school with impulsive behaviour and lack of focus. Dale intuitively felt it had something to do with his diet. When he contacted me the behaviours were impacting his son’s relationships at home, as well. The entire family was upset by his acting out and it was difficult to know how to manage. Dale reached out to try nutrition before turning to stimulant drugs that were being requested by the school and prescribed by the family physician.

After working together for three months his son’s behaviours were so much better he didn’t need the prescription or any other intervention. The school was happy and so were the family. The only change was the family dietary habits – and they changed considerably. So today I’m going to share through Dale’s story the power of nutrition to impact mood, attention, and behaviour in children and youth. But first I want to share a bit about my recommendations.

While I know it’s difficult to change dietary habits for an entire family this is what I advocate unless we’re talking about a super strict ketogenic diet for seizure management or an extremely restricted diet for a chronic disease state. Why? Well, changing the diet of just one child or person in a household is impractical in terms of budget and time and meal creation, and it invariably creates conflict. For a healthy diet to succeed long term, it needs to not be perceived as a restriction but as a new way of life. This is much easier in a family model when every person in the home reaps the benefits of the dietary changes. When they all feel better and have improved health they can all come on board to reinforce the new diet – and the person who needs the change the most feels less restricted and more supported.

Let’s be honest, there’s little that’s more demoralizing when you’re restricted in what you can eat than watching someone else enjoy it! But once you have normalized a new pattern of eating for an entire family, it’s much easier to maintain and enjoy. In this model, if one person feels like slipping there are others to reinforce the change. It’s a superior model all around.

This model works for families with diabetes and mental health and weight loss issues, as well. There are never members of a family that won’t also benefit from a better diet even if they don’t have the same symptoms! While they may not have weight issues or diabetes, they will almost always have their own health issues – skin troubles or digestive troubles or sleep troubles or mental health issues or heart issues or blood pressure concerns. These are all related to diet, too! That’s because food isn’t like medicine. Food is medicine. And the things we put in our mouths day in and day out build good health or poor health over time. The problem is that we often wait until our health is in crisis because of our dietary habits before we honour our bodies enough to make serious change.

Back to Dale’s story, his family was in crisis. His other children were becoming resentful of let’s call him Simon. And Simon was so tired of being the bad kid no matter what he did that he had become defiant. When children are punished for outbursts and don’t feel it’s safe to be angry they often become passive about expressing it. Defiance is one such expression. I learned this first hand with my son.

Think about it. Why would a child who gets the message that he is never good enough to please anyone set himself up for the heartbreak of trying to please anyone? Why would the child care anymore? Why even try? Enter defiance. This can include selective listening, damaging the home and other people’s possessions openly or in secret, stealing, tantrums, sabotaging family events, accidentally ruining things, and more. It can even escalate to hurting the family pet or smaller siblings if the anger goes deep enough. This is a child who has internalized the message he is bad. And worse, he’s believed it.

And the frustration may be coming from school, not home. Teachers may not realize it, but they have tremendous power. In the words of teacher and child psychologist and psychotherapist, Haim G. Ginott:

“I have come to the frightening conclusion that, as a teacher, I possess a tremendous power to make a child’s life miserable or joyous. I can be a tool of torture or an instrument of inspiration. I can humiliate or heal. In all situations, it is my response that decides whether a crisis will be escalated or de-escalated and a child humanized or dehumanized.”

This is all the more true of children who are suffering to control their own actions and mind. And when food intolerances are involved, that is precisely the case.

A child with food intolerances has a brain and central nervous system that is on fire.

They also often have fasting hypoglycemia, an early symptom of insulin resistance. Together these can cause a host of symptoms from brain fog and learning disabilities to absence seizures to a short fuse to wildly oscillating moods and outbursts.

Try to think of the adult equivalent. Have you ever tried to have self control when extremely intoxicated or insanely caffeinated? Have you ever tried to have self control when you’re hangry at the end of a long, bad, day and someone expects you to do something you can’t? As adults our self control mechanisms are much more developed than those of children. Imagine how difficult – no impossible – these scenarios are for their developing brains! This is what such a child is struggling with.

I know this because I saw it with my son. His behaviour was so violent, so extreme that workers who helped manage his care were worried he had a sociopathic personality. No medication helped. No treatment helped. But dietary changes turned it around inside of a month. When the offending foods were removed, a different child emerged.

In Dale’s case, Simon also had several food intolerances. Normal allergy testing had been conducted via skin prick tests but this didn’t help the family in any way. I find these tests unhelpful in the case of food intolerances. I prefer bioresonance hair analysis for food intolerances coupled with blood IgA and IgG testing, which tells us which foods are causing delayed reactions in the body. They can take hours to show up and create inflammation. This can show up as skin problems, vascular problems, digestive problems – and you guessed it – brain problems.

Most people are aware of blood allergy testing. This is for IgE antibodies, which we associate with immediate reactions. Think hives, throat swelling, and anaphylactic reactions. IgG testing, on the other hand, looks for delayed reactions to the proteins in foods. The reaction triggers an immune cell reaction, but it takes time. And to complicate matters even more, our level of sensitivity to these foods changes in relation to how frequently we are exposed to them and how overloaded our body is at that time.

IgA testing is testing for irritation to the mucous membranes, as that is where these immunoglobulins reside. They signal irritation and inflammation of the digestive tract. They are frequently associated with gluten intolerance and gut biome issues. I then use bioresonance hair testing to get a clearer picture of best foods and start a guided elimination diet – which is really the gold standard to determine intolerances.

A good elimination diet is going to eliminate all the likely offenders. These include wheat, gluten, dairy, soy, corn, eggs, sugar, artificial flavours and preservatives,

colouring foods, artificial sweeteners, chocolate, beans, tomatoes, and peanuts. As you can see, the list is extensive, so it should only be undertaken with professional oversight. We do not want to remove nutrients the child needs for normal development.

In Simon’s case, gluten and corn were the big offenders. Dairy was a secondary intolerance, but we healed that over time. Of course, this ruled out almost all processed and convenience foods, so it’s easy to see how he was triggered all the time. He also had reactive hypoglycemia, which is common in children with strong sweet cravings. Once weaned off sweets and foods with these ingredients an entirely new boy emerged. He was affectionate and more calm. He was able to listen and follow directions. The message he got as a result was that he was not a bad boy, after all. He was just sick and needed a special diet. He, and his whole family, were relieved. His siblings were able to bond with him and the family dynamic was completely transformed. That’s the power of nutrition interventions! The dietary changes impacted the whole family, but it was well worth the pay off! This echoes my own experiences with my son.

The science backs this up. From Diet Modification impact on ADHD outcome by Olweya Mohammed Abd El Baaki et al, published in Bulletin of the National Research Centre in 2021:

“Food affects children’s behavior in different ways such as food allergy, food intolerance and gut–microbiota–brain axis (Petra et al. 2015). Food allergy causes increased levels of antigen-specific immunoglobulins and mast cell marker in the brain and these brain allergic responses are associated with behavioral impairments, including motor and learning deficits (Costa-Pinto et al. 2012).

Food intolerance is an adverse physiologic response to a food due to inherent properties of the food (i.e., toxic contaminant, pharmacologic active component) or characteristics of the host (i.e., metabolic disorders, idiosyncratic responses, psychological disorder). However, there is evidence that some children respond adversely to particular items of food with behavioral consequences and reactions that may occur for many reasons (Ortolani and Pastorello 2006).”

I hope this is helpful for families who are struggling with children with behavioural issues. Dietary interventions are inexpensive, infinitely more safe than pharmacological interventions and have no negative side effects. Given that they have shown to be effective I am a staunch advocate for using them prior to mind altering drugs.

As always, I welcome reader health and nutrition questions for the column. You can email me at [email protected] and can find me online at


Nonie Nutritionista

Next Post

Beer and spirits have more detrimental effects on the waistline, cardiovascular disease risk than wine | Health

Researchers are working to tease apart how various alcohol types contribute to weight gain and disease risk. pixhook/E+ via Getty Images The Research Brief is a short take about interesting academic work. The big idea Drinking beer and spirits is linked to elevated levels of visceral fat – the harmful […]