3 Nutrient Deficiencies That Can Fuel Picky Eating

As a pediatric nutritionist – and a mom of three – I’ve seen picky eating from both sides of the table.

At one point, my daughter would barely eat anything beyond crackers, cucumbers, and blueberries. Dinner often ended in frustration, bribery, or tears (mine and hers). Sound familiar?  And now, having worked with thousands of families (especially parents with picky eaters), it’s clear that and selective eating or “food fussiness” aren’t just related to sensory processing, behavioural challenges, a need for control, or bad habits.  There’s often childhood nutrient deficiencies at play.

Don’t get me wrong.  I have tremendous respect for pediatric doctors (they helped us in many other ways!).  But here’s the thing: Many pediatric specialists (including other picky eating experts) don’t realize that nutrient deficiencies contribute to picky eating.  

There are a few key nutrients that can contribute to picky eating habits. Let’s take a look at what they are:

The Hidden Link Between Nutrient Deficiencies and Picky Eating

Many parents assume picky eating is just a developmental phase or genetics – and sometimes, it is. But what if part of the problem is happening inside your child’s body?

Research shows that low levels of certain nutrients can actually worsen picky eating behaviors by impacting taste, appetite, sensory processing, and mood.

Let’s talk about three of the most overlooked nutrient deficiencies: Iron, Zinc, and Omega-3s.

Iron: The Energy and Appetite Connection

Iron plays a vital role in transporting oxygen throughout the body and supporting brain development. But here’s what’s lesser known: Iron deficiency can cause fatigue, irritability, and reduced appetite — a perfect storm for picky eating.

According to the World Health Organization, iron deficiency is the most common nutritional deficiency worldwide, especially in young children and women (WHO, 2008).

In my daughter’s case (and many other children I work with), low iron wasn’t just affecting their energy — it was actually dulling their appetite and motivation to try new foods. In fact, I see children with low iron who are also pretty energetic on most days.

Once we added more iron-rich foods and strategies to ensure iron, I started to notice small shifts. Including that they seem more open to tasting new things and eating more overall. Kids still have their preferences (don’t we all?), but the food resistance starts to ease.

Symptoms of iron deficiency:

• Abnormal paleness or lack of color of the skin
• Irritability
• Lack of energy or tiring easily (fatigue)
• Increased heart rate (tachycardia)
• Sore or swollen tongue
• A desire to eat peculiar substances such as dirt or ice (pica)

Iron-Rich Foods (for energy, brain development, and immunity)

• Lean red meat (meatloaf, burgers, or tacos)
• Chicken/turkey (especially dark meat)
• Lentils (hidden in pasta sauce or soups)
• Spinach (blended into smoothies or pasta sauce)
• Iron-fortified cereals (like Cheerios or oatmeal)
• Tofu (in stir-fries or baked with seasoning)
• Dried apricots (chopped into snacks or muffins)
• Beans (in quesadillas or hummus form)

🧃Tip: Pair plant-based iron foods with vitamin C-rich foods (like strawberries or bell peppers) to increase absorption.

 

Zinc: The Taste and Texture Game-Changer

While it’s not a nutrient we talk about a lot, zinc plays a key role in taste perception and appetite regulation.  Kids with low zinc levels can experience altered or heightened taste — sometimes even a metallic or bitter taste — which can make certain foods completely unappealing (Hambidge et al., 1986).

When I think about my Nonna (that’s grandma in Italian), I remember how much she used to love food. We’d sit in her basement kitchen, sharing homemade gnocchi and other delicious Italian meals.  But as she aged, her appetite faded, and she ate less and less. Eventually, she became more frail and weak. It’s a pattern we often see in the elderly.

One key reason? A decline in taste acuity — and a common culprit behind that is zinc deficiency, which becomes more prevalent with age.  If you want to dig into the research, click here.

Basically, zinc plays a crucial role in maintaining our sense of taste, and when levels drop, food can start to taste bland, bitter, or just “off.”
This doesn’t just happen to our grandparents – it can happen to kids, too. And when food doesn’t taste right, it’s no wonder they don’t want to eat it.

Interestingly (while iron deficiency tends to be the focus with kids’ nutrition) this study with children aged 4-7 years old showed that the prevalence of zinc deficiency (37.4%) is much higher than that of iron (16.3%).  And, get this…children with zinc deficiency were significantly associated with picky eating behaviours, lower development levels and poor physical activity.

It doesn’t stop there!  Zinc is also required for producing stomach acid which is needed for digestion and absorption of nutrients. So a zinc deficiency can cause digestive symptoms that contribute to irritability.

This is why, when I work with families to improve their nutrition (and picky eating), we measure their zinc consumption through food journal assessments and I provide personalized recommendations to improve their zinc intake and absorption.

Symptoms of zinc deficiency:

Omega-3s: Supporting Brain and Sensory Processing

Over 60% of the brain is made up of fat and the Omega-3 fatty acid DHA (docosahexaenoic acid) makes up around 10-15% of this. Needless to say, DHA is necessary for the development of the sensory, perceptual, cognitive, and motor neural (nerve) systems during the brain growth spurt.  It’s why we see DHA (and all omega-3s) prioritized for young children.

This is also why we hear so much about healthy fats for neurodiverse children, particularly those with ADHD.  In fact, an article published in 2019 that combined doses of EPA & DHA equal to or above 750mg per day over 12 weeks have shown significant improvements of symptoms of ADHD.

Taking it a step further, children with low omega-3 levels may be more sensitive to food textures, smells, or temperatures, which can make meals feel overwhelming.

Consider boosting omega-3s (preferably from fatty fish which is more absorbable).  You can also leverage flax, chia, or supplements to support your child’s brain, and as a result, their eating.

Symptoms of omega-3 deficiency:

• Rough or dry skin
• Brittle or peeling nails
• Hair loss or brittle hair
• Sleep issues
• Mood swings, anxiety, depression
• Brain fog and trouble concentrating
• More frequent illness

Omega-3 Rich Foods (for brain health and sensory processing)

• Salmon (salmon patties, salmon salad, or mixed with mashed potatoes)
• Canned light tuna (made into melts or with crackers)
• Chia seeds (in smoothies, puddings, or oatmeal)
• Ground flaxseed (added to muffins or yogurt)
• Walnuts (chopped into pancakes or trail mix)
• Omega-3 enriched eggs
• Hemp seeds (sprinkled on toast, cereal, or blended into smoothies)

The Big Picture: It’s Not Just Pickiness

When nutrient levels are low, your child’s resistance to food may not be defiance — it could be a biological response. Their body is simply trying to cope with how food feels or tastes to them.

This is why in my private work with families, I offer something called The Inside Scoop — a personalized Nutrition Assessment that looks beneath the behavior to uncover possible nutrient gaps that might be driving your child’s eating challenges. Because sometimes the fastest way forward isn’t more strategies…it’s supporting your child from the inside out.

What You Can Do

If you’re navigating picky eating at home, here are a few next steps you can take:

• Watch for signs of nutrient deficiencies – like fatigue, pale skin, poor focus, low appetite, or frequent illness.
• Offer iron and zinc-rich foods – like red meat, lentils, pumpkin seeds, eggs, and fortified cereals.
• Consider a professional Nutrition Assessment – to identify hidden gaps that may be holding your child back.

And above all — don’t blame yourself.

I know how hard it can be when you’re trying your best and still feeling stuck. I’ve been there. But there is a way forward. And I’d be honoured to help.  Email info@daniellebinns.com learn more about “The Inside Scoop” and getting insights into your child’s nutritional gaps (deficiencies and excesses) without needed a poke (blood draw).

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How The Inside Scoop works:

Get a Personalized Nutritional Assessment for Kids – so you can have clarity and peace of mind that your child is getting the nutrients they need to be good eaters and thrive.

Step 1: Food Journal

• Send me a 1–2 day food journal for your child. Try to pick a fairly typical eating day, and be as specific as possible — include portion sizes, brands, and how the food is prepared (e.g., “½ cup of Annie’s mac and cheese + 3 green beans”). You can upload it right here.

Step 2: Assessment

• Once I receive your journal, I’ll get to work behind the scenes and put together a personalized Nutrition Assessment. It will include an easy-to-understand traffic light rating system (green/yellow/red) and show how your child is doing in these key areas:
  • Protein
  • Fiber
  • Sugar (goal: under 25g daily)
  • Fats (with a focus on healthy fats)
  • Carbohydrates
  • Iron
  • Zinc
  • Calcium
  • Omega-3s

Step 3: Payment

Because of the time and detail involved, this assessment is typically $400 USD. However, I’m offering a significantly reduced rate for a limited time to support more families in understanding and improving their child’s nutrition.  There are two ways I can support you:

• Nutrition Assessment Only – $190 CAD
• Nutrition Assessment + 30-min Phone Review – $290 CAD  (includes a one-on-one call to walk through the results, review food recommendations to close nutrient gaps for your child, and outline practical next steps)

If you have any questions, feel free to email info@daniellebinns.com   Looking forward to diving into your child’s nutrition and helping you uncover any hidden gaps (and easy wins!).