Simply Salt and Soul

When we talk about children’s mental health, we usually focus on things like therapy, screen time, sleep, and school pressure. But there’s another part that doesn’t always get as much attention—nutrition.

There’s more and more research looking at how what kids eat can influence things like brain function, emotional regulation, stress response, and overall mood. It’s not the only piece, and it’s definitely not a quick fix—but it’s part of the bigger picture. And over time, it can shape how kids feel day to day.

This is something that’s getting more attention now. Universities are studying it, and it’s showing up more in research. We’re also seeing more clinicians include nutrition as part of the bigger picture when it comes to mental health.

For example, large population studies have found that people who follow more whole-food patterns, like a Mediterranean-style diet, tend to report lower rates of low mood compared to those eating more ultra-processed foods. In one clinical trial, adults who shifted their eating patterns toward more vegetables, whole grains, legumes, and healthy fats showed noticeable improvements in mood over about 12 weeks compared to a control group receiving social support.

There’s also growing research looking at the gut-brain connection. The gut microbiome plays a role in producing neurotransmitters and regulating inflammation, both of which are linked to how we feel day to day. So when we talk about food, we’re not only talking about physical health, we’re also talking about how the brain is supported on a daily basis.

When you start to understand what’s going on underneath, it starts to make more sense. The gut and brain are constantly communicating. Certain nutrients support the production of brain chemicals linked to mood and focus, and when those levels are low, you can feel the difference.

Where Canadian Children’s Mental Health Stands

First, just a bit of context—when it comes to children’s mental health in Canada, the numbers are significant… and they’ve been getting worse in recent years.

In Canada, about 1 in 5 children and youth are dealing with some form of mental health challenge. Even before COVID, there was already a rise in ADHD diagnoses, especially in boys, along with anxiety, low mood, and a growing need for support. Since the pandemic, that has added another layer, with more families looking for help and resources.

The 2019 Canadian Health Survey on Children and Youth found that among children aged 5 to 11:

7.6% had been diagnosed with ADHD
3.4% had an anxiety disorder or depression
2.5% had autism spectrum disorder
Overall, 10.9% had at least one diagnosed mental health condition

Those numbers were from before the pandemic. More recent data still shows high rates of mental health challenges and neurodevelopmental conditions in kids. Anxiety continues to come up as one of the most common long-term concerns, especially in school-age children. Overall, it’s still around 1 in 5 kids in Canada, and for some, it affects their day-to-day life in a noticeable way.

What’s going on in our kids’ brains isn’t separate from what they’re eating, and that connection is getting more attention now.
When you look at the data, only a small percentage of kids, around 2%, have diets considered high quality. Most fall into a “needs improvement” range. So there’s a gap between the kind of nutrition that supports how they feel day to day, and what a lot of them are actually getting.

The Gut-Brain Connection

Here’s something that can help make sense of it. Your child’s gut and brain are always talking to each other. This is what people call the gut–brain connection (gut–brain axis). It’s basically a two-way connection between the digestive system and the brain, with the vagus nerve playing a big role in how those signals move back and forth.

The gut is sometimes called the “second brain,” and there’s a reason for that. It actually has its own nervous system built right into the gut, with hundreds of millions of nerve cells. It can function on its own in a lot of ways—but it’s also in constant communication with the brain.

Most people don’t realize this, but many of those brain-related signals connect back to the gut. The gut helps produce and regulate things like serotonin, dopamine, and GABA, which are linked to mood, focus, and how we handle stress. It also plays a role in how inflammation is managed in the body.
That doesn’t mean the gut controls how your child feels, but it is part of a larger system that influences mood, energy, and emotional balance over time.

What kids eat plays a role in that environment. Diets higher in processed foods and lower in fibre can shift the balance of gut bacteria, while more whole, fibre-rich foods tend to support a healthier mix. Because the gut and brain are connected, changes in that internal environment can influence how those signals move back and forth.

There’s also research looking at how the gut connects to the blood–brain barrier, the layer that helps control what gets into the brain. When the gut is out of balance, it can influence how well those protective systems function. It’s not a simple cause-and-effect relationship.

But it’s one way researchers are starting to connect what’s happening in the body with how the brain responds over time. All of this means that taking care of a child’s gut is taking care of their brain. The two are not separate systems. What you feed the gut, you feed the mind.

Diet and Teen Mental Health

Here’s a study worth paying attention to. Researchers from the University of Toronto, University of Alberta, University of Waterloo, and Brock University followed nearly 14,000 Canadian adolescents over two years, looking at diet and mental health.

What they found was interesting. Teens who were drinking more sugary beverages tended to report more intense symptoms of anxiety and low mood—especially boys. On the flip side, those eating more fruits and vegetables generally reported better overall wellbeing. And what stood out is that these patterns were still there even after accounting for other lifestyle factors. (Dabravolskaj et al., 2024)

Researchers pointed to diet, especially reducing sugary drinks and increasing fruits and vegetables, as something to include in the bigger picture when supporting mental health in teens. Not as a side note, but as part of the overall approach. There’s also Canadian data on food insecurity, which many families are dealing with right now. In one national study, kids living in households where food wasn’t always consistent were more likely to have diagnosed mood and anxiety concerns.

This doesn’t mean food is the only reason behind those outcomes, but it does show a pretty consistent link between having access to food and how kids are feeling mentally.

The Nutrients That Matter Most for Children’s Mental Health

This is where we can get a little more specific. The gut–brain connection matters, but at the end of the day, nutrients are the actual building blocks. So let’s walk through what the brain needs, what each one does, and where to find them.

Omega-3 Fatty Acids — DHA and EPA

Your brain is made up of a lot of fat (around 60%), and one of the most important types is DHA. It’s a core building block, actually forming part of your brain cells and helping them communicate with each other. EPA plays a different role. It helps support how the body responds to inflammation, which can shape how the brain functions over time.

Omega-3s are one of the areas where research has been pretty consistent when it comes to kids and mental health. What tends to show up is that lower intake is often linked with more challenges around things like attention, mood, and anxiety. In some studies, adding EPA and DHA has been shown to support things like focus, behaviour, and overall mood in kids who are already struggling in those areas.

When omega-3 levels are low, it’s often linked with things like inattention, impulsivity, emotional ups and downs, and low mood in kids. The need for DHA is also higher during certain stages like infancy, early childhood, and adolescence, when the brain is growing and developing quickly.

Where to find them?

Fatty fish like salmon, sardines, mackerel, and trout are some of the best sources. A couple of servings a week is often enough to support intake. If your child doesn’t eat fish, a good quality fish oil supplement is something to consider. Plant sources like walnuts, flax, and chia also contain omega-3s, but it’s a different type. The body doesn’t convert it as efficiently, so they’re still great to include, just not quite the same.

Magnesium — the Calming Mineral

Magnesium plays a role in hundreds of processes in the body, including some that are closely tied to the nervous system and stress response. It helps support calming signals in the brain and how the body handles stress overall. When levels are lower, it’s often associated with anxiety, irritability, sleep difficulties, and more emotional ups and downs in kids.

Here’s the part that often gets overlooked. Magnesium is found in foods like whole grains, nuts, seeds, legumes, and leafy greens, foods many kids aren’t eating enough of. On top of that, stress can use up magnesium more quickly. So a child under more pressure, school, social, or just a busy schedule, might need more at the same time they’re getting less. It’s not always obvious, and it tends to build gradually, often showing up in mood, sleep, or behaviour before nutrition even comes into the conversation.

Best food sources: dark chocolate (yes, really), almonds, cashews, pumpkin seeds, black beans, spinach, edamame, banana, whole grain bread
For children with significant anxiety or sleep issues: magnesium glycinate supplement 100–150 mg before bed is often recommended by integrative practitioners and is very well tolerated

Zinc

Zinc plays an important role in how the hippocampus develops and functions, the area of the brain linked to learning, memory, and emotional regulation. It also supports the production of serotonin and GABA. Lower zinc levels have been linked with depression and anxiety in both children and adults.

Research has found that children with ADHD often have lower zinc levels than their peers. Some clinical trials suggest that adding zinc as part of a broader approach may help support attention and behaviour. It’s not meant to replace other supports, but it highlights how important nutrition can be.

Best food sources: meat, poultry, oysters, lentils, chickpeas, hemp seeds, pumpkin seeds, cashews
Vegetarian and vegan children are at higher risk of zinc deficiency and may benefit from supplementation or consistent attention to plant-based zinc sources

Iron

Iron deficiency is one of the most common nutrient gaps in children globally, and it can affect both brain function and mental well-being. Iron plays a role in building myelin (the protective coating around nerve cells), as well as in making dopamine and carrying oxygen to brain tissue. When levels are lower, these processes don’t work as efficiently.

Children with low iron, even before it reaches anemia, can experience difficulties with attention, working memory, learning, and behaviour. Research has also found a consistent link between low iron status and ADHD symptoms. Anxiety and irritability can show up as well, though they’re often connected to other factors and not always linked back to nutrition.

Best food sources: red meat, liver, dark poultry meat, lentils, beans, tofu, fortified cereals, dark leafy greens
Always pair plant-based iron with vitamin C (lemon juice, bell pepper, kiwi, tomatoes) to significantly enhance absorption
Avoid tea and coffee within an hour of iron-rich meals as tannins block absorption
If deficiency is suspected: get ferritin tested, not just hemoglobin. Ferritin reflects stores and drops before anemia appears

B Vitamins — B6, B12, and Folate

B vitamins are important for brain health. They support neurotransmitter production and are involved in the methylation cycle, a process linked to mood regulation, how the body responds to stress hormones, and cellular repair. More specifically:

B6 (pyridoxine): Helps make serotonin and GABA — supports mood and calm
B12: Essential for myelin production and nerve function. Deficiency is linked with depression, irritability, and cognitive decline. Vegetarian and vegan children are at higher risk.
Folate (B9): Helps produce serotonin and dopamine — supports mood and emotional balance

Sources: B6 from poultry, fish, potatoes, banana, chickpeas. B12 from animal products — meat, fish, eggs, dairy (no reliable plant sources, supplementation is mandatory for plant-based children). Folate from dark leafy greens, lentils, asparagus, avocado, fortified cereals.

Vitamin D

Vitamin D is a bit different from other nutrients—it functions more like a hormone and can cross into the brain, where it interacts with areas involved in mood and thinking. Lower levels have been linked with depression, anxiety, and cognitive difficulties in a number of studies. And in Canada, with less consistent sun exposure, many children are more at risk of being low.

More than 90% of Canadian children aged 4 to 8 are not meeting the Estimated Average Requirement for vitamin D. For a nutrient involved in brain chemistry and inflammation, that’s worth paying attention to. Supporting daily intake, around 600 IU, with some practitioners suggesting up to 1,000 IU year-round, can play a role in overall physical and mental well-being.

Probiotics and Prebiotics

When you look at the gut–brain connection, it makes sense that supporting the gut microbiome could play a role in children’s mental health. And this is an area where research is growing quickly.

In some recent studies, children who were given specific prebiotics showed improvements in certain social behaviours, particularly among those with ASD. Other reviews of clinical trials have also found general improvements in behaviour and autism‑related symptoms with certain probiotic strains.

Psychobiotics, probiotic strains linked to mental health, are getting more attention in research. Strains like Lactobacillus rhamnosus, Bifidobacterium longum, and Lactobacillus helveticus have been studied for their role in stress and anxiety, mainly in adults and experimental models, with emerging research in children.

That doesn’t mean every child needs a supplement, but it does highlight the value of including fermented foods, prebiotic fibre, and a variety of foods to support brain health through the gut on a daily basis.

Probiotic foods: plain yogurt with live cultures, kefir, sauerkraut, kimchi, miso
Prebiotic foods (feed the good bacteria): garlic, onion, leeks, asparagus, banana, oats, lentils, chicory
Fibre diversity: the more different plant foods your child eats across a week, the more diverse the microbiome

Protein and Amino Acids

Neurotransmitters are made from amino acids, which come from protein. Serotonin is synthesized from tryptophan, dopamine from tyrosine, and GABA from glutamate. Without enough consistent protein in the diet, the brain can struggle to maintain the steady supply of neurotransmitters it needs to support mood, attention, and the stress response.

This is especially relevant for kids who are skipping breakfast, relying mostly on high‑carbohydrate, low‑protein meals, or following plant‑based diets without enough protein planning. A bowl of cereal in the morning and a granola bar for lunch might seem like enough, but it doesn’t give the brain a steady supply of amino acids across the school day.

Protein at every meal is a foundational principle for brain health — especially breakfast
Best sources: eggs, meat, fish, poultry, yogurt, legumes, tofu, tempeh, cheese
Aim for 15–20g of protein at breakfast specifically to support stable neurotransmitter production and blood sugar through the morning

The Foods That Work Against Mental Health

Ultra-processed food and sugar

This is probably the piece that matters most, and the one most kids in Canada are exposed to every day.

Ultra-processed foods, things like packaged snacks, fast food, sugary cereals, flavoured drinks, processed meats, chips, and cookies, are designed to taste appealing, but they don’t offer much in terms of nourishment. They’re usually lower in fibre, vitamins, minerals, and healthy fats, and higher in refined carbohydrates, added sugars, processed oils, and additives that can affect the gut and overall balance in the body.

At a basic level, it’s fairly straightforward. Sugar can lead to quick rises and drops in blood sugar, which can affect mood, energy, and focus. Over time, higher intake may also shift the balance of gut bacteria. And because of that gut–brain connection, those changes can influence things like inflammation and how the brain responds to stress.

It’s worth being honest about how common this is in kids’ everyday lives. It shows up at school, at birthday parties, in lunchboxes, in sports bags, on the way home from practice—it’s everywhere. The goal isn’t to avoid it completely; it’s to make sure most of what a child eats is real, nourishing food, so these kinds of foods stay occasional, not the default.

Sugar-sweetened beverages — the most direct target

When it comes to diet and children’s mental health, sugar-sweetened beverages show up again and again in the research. Things like sports drinks, sodas, flavoured juices, energy drinks, and sweetened iced teas are essentially concentrated sources of sugar with little nutritional value. They’ve been consistently linked with higher rates of depression and anxiety in youth. They’re also one of the simplest places to start. Swapping to water, sparkling water with fruit, or diluted juice can make a noticeable difference over time.

Food dyes and additives

This is one of those topics where the research isn’t completely clear cut, but there’s enough there to pay attention to.
Certain artificial food dyes, like Red 40, Yellow 5, and Yellow 6, have been linked in some studies to increased hyperactivity and inattention in some children. In the UK, manufacturers were encouraged to remove these additives after that research came out. That hasn’t happened in the same way here, so these dyes are still commonly used in Canada. You’ll still hear many parents say they notice a difference in behaviour and focus when these are removed.

Beyond dyes, other ingredients in ultra-processed foods, like emulsifiers, preservatives, and artificial flavours, can affect the gut microbiome. That, in turn, can influence mood and how the brain functions. These changes aren’t obvious or immediate. They tend to build over time in quieter, more subtle ways.

Skipping breakfast and irregular eating

The brain relies on a steady supply of glucose to function well. When a child skips breakfast or goes several hours without eating, blood sugar can drop, and the body compensates by raising cortisol. This can put the brain into more of a stress response, and it shows up in ways like irritability, trouble focusing, anxiety, emotional ups and downs which may often be mistaken for behaviour or personality, when the fact is, they simply haven’t eaten.

Breakfast sets the tone for the first half of the school day. It supports neurotransmitter production and helps keep blood sugar more stable. A higher-protein, lower-sugar breakfast, like eggs, yogurt, whole grain toast with nut butter, or a smoothie with protein, creates a steadier start compared to sweetened cereal or skipping breakfast.

Nutrition and Specific Mental Health Conditions in Children

ADHD and Nutrition

ADHD is the most commonly diagnosed neurodevelopmental condition in Canadian children, affecting about 7.6% of those aged 5 to 11. While it has strong genetic and neurological roots, nutrition can still play a supporting role in how symptoms show up.

Research tends to point to lower levels of nutrients like omega-3s, zinc, iron, and magnesium in kids with ADHD. These aren’t the cause, but they can influence things like attention, impulse control, and behaviour. Omega-3s in particular (EPA and DHA), have shown some consistent benefit in supporting these areas, even if the effects are more subtle than medication.

Some families also notice improvements when reducing artificial food dyes and cutting back on refined sugar, though the research here is more mixed. Overall, a balanced diet with enough protein, complex carbohydrates, and omega-3-rich foods (and less reliance on ultra-processed foods), is the most supported approach.

Anxiety and Nutrition

Anxiety in children is connected to the gut–brain connection, the stress response system, and the balance between more stimulating and more calming signals in the brain. Nutrients like magnesium, along with the body’s own calming signals like GABA, play a role here. When magnesium is low and the gut is out of balance, it can be harder for the body to settle out of a heightened stress state.

Some Canadian data has also linked higher intake of sugar-sweetened beverages with more severe anxiety in adolescents. On the other hand, more balanced, anti-inflammatory eating patterns—rich in omega-3s, fibre, and whole foods—are being explored as ways to support anxiety, alongside other supports like therapy.

Depression and Nutrition

When it comes to depression in young people, diet quality is one of the more consistent factors that shows up in the research. A 2025 review in Frontiers in Nutrition found that adolescent depression is linked with imbalances in the gut microbiome, and that changes in gut–brain signaling may play a role in symptoms like low mood, reduced enjoyment, and social withdrawal.

In the research, a few nutrient gaps come up consistently in depression, particularly omega-3s, folate and B12, vitamin D, iron, and zinc. These can often be supported through diet and sometimes supplementation, alongside professional mental health care, not instead of it. It makes sense to include nutrition as part of the conversation when looking at a child’s mental health.

Autism Spectrum Disorder and Nutrition

It’s common for children with ASD to have digestive challenges, more selective eating, and differences in their gut microbiome. This is part of why the link between gut health and ASD symptoms has become such an important and growing area of research in both nutrition and paediatric mental health.

Practical Steps for Every Family

Build meals around protein and real food

Including protein at each meal, especially breakfast, makes a difference. Foods like eggs, Greek yogurt, salmon, chicken, lentils, tofu, or cheese provide the amino acids the brain uses to make neurotransmitters, and help keep blood sugar more stable.
It creates a steadier foundation for the day compared to starting with something like cereal and juice.

Make the swap from sugary drinks to water

Given how consistently sugar-sweetened beverages show up in the research on depression and anxiety in Canadian youth, this is one of the simplest and most impactful changes families can make. Making water the default, using sparkling water with a bit of juice as a treat, and keeping things like soda, sports drinks, and sweetened juices as occasional can go a long way. It may seem simple, but over time, this change can make a noticeable difference in mood and focus.

Serve fish at least twice a week

Fatty fish like salmon, trout, sardines, and mackerel are some of the best sources of EPA and DHA, the omega-3s most closely linked to brain health and mood. If fish isn’t going to happen regularly, a good quality fish oil supplement in the range of 250 to 500 mg of combined EPA and DHA is something to consider. This is one of the more impactful nutritional areas to focus on when supporting a child’s mental well-being.

Go heavy on plants and variety

The gut microbiome depends on fibre and plant diversity. The more variety your child gets, vegetables, fruits, legumes, whole grains, nuts, and seeds, the more supported and balanced that system becomes. That can influence how the gut and brain communicate. Even aiming to include a range of plant foods over the week helps.

Include fermented foods regularly

Full-fat plain yogurt with live cultures is often the most accessible probiotic food for kids and easy to include daily. Kefir in smoothies is another option. You can also slowly introduce foods like miso in soups, mild kimchi, or small amounts of sauerkraut, depending on your child. These foods help support the gut microbiome by adding beneficial bacteria. While not every child will take to them right away, even small, consistent exposures can be meaningful over time.

Supplement strategically for Canadian kids

Given our geography and the data on where Canadian children are consistently deficient, these are the supplements most worth considering:

Vitamin D3: 600 to 1,000 IU daily, year-round for most Canadian children. Non-negotiable given our sun exposure and its direct role in brain chemistry and mood.
Omega-3 (EPA and DHA): if fish isn’t being eaten regularly. Nordic Naturals and Carlson Kids are quality children’s brands widely available in Canada.
Magnesium glycinate: particularly for children with anxiety, sleep difficulties, or significant emotional dysregulation. 100–150 mg before bed.
Iron: only if deficiency or low ferritin is confirmed by testing. Don’t supplement without knowing levels.
B12: essential and mandatory for children following vegetarian or vegan diets. No reliable plant-based B12 sources exist.

Eat together as much as possible

This part goes beyond nutrition. It’s really about mental health, too. Eating together as a family is consistently associated with better outcomes for kids and teens. It’s not just about the food, but the connection, the conversations, and the calm, structured time together. Even a few shared meals each week can make a difference in ways that aren’t always obvious.

One in five Canadian children is living with a diagnosed mental health condition. Rates of anxiety and depression have been rising for years, with a clear increase during the pandemic. At the same time, research is placing more attention on everyday nutrition as one piece of the picture, shaping brain function, emotional regulation, and how children respond to stress over time.

Diet isn’t the answer to everything. Therapy, support, sleep, and connection are all essential. There’s no single solution when it comes to a child’s mental health. But nutrition is a foundational layer that’s often underestimated by families, schools, and even healthcare. The evidence is strong enough that it shouldn’t be left out of the conversation.

The gut helps produce serotonin, the microbiome influences inflammation, and key nutrients support the brain systems involved in mood and focus. A diet built on ultra-processed foods and low fibre creates a different foundation than one based on whole, balanced meals. Over time, that difference can show up in behaviour, focus, and emotional regulation. This is reflected in the research and something many parents notice at home.

Feed the gut. Support the brain. The two are connected, and starting early helps build a stronger foundation over time.