One of the most common challenges when it comes to a child’s nutrition is fussy eating. Sometimes, this can come down to the behaviours and habits of both the child and the rest of the family. But most of the time, picky eaters aren’t just wanting to be a source of frustration for you. There are physiological imbalances that can cause fussy eating habits.

Watch the video below or keep reading to learn more about the underlying causes of fussy eating.

Fussy eating is most common in the toddler years. By age 2, a child’s growth rate will drop, and their nutrient and calorie needs drop with it. Most children will grow out of picky eating in time, but it can be frustrating when you make them nutritious, yummy food that they won’t eat!

Different kids will have different taste preferences. And although there are many strategies that can help reduce their fussiness, what works for one child won’t work for another. It’s a trial and error process to come up with what will work with your child. But by understanding what might be underlying their picky eating, you can start to address the root cause of the behaviour.

The 3 Underlying Causes Of Fussy Eating

Nutrient deficiencies

Parents of fussy eaters will often be worried their child is at risk of nutrient deficiencies. But it goes both ways – low nutrient levels can lead to fussy eating habits. There are several nutrients that can alter appetite and encourage picky behaviours around food.


The number one nutrient deficiency to think about is zinc. Kids have a massive need for zinc – it plays a role in the growth, development and repair of the body. A zinc deficiency can lead to reduced appetite and picky eating. Zinc is also required for producing stomach acid, so a deficiency can cause digestive symptoms that contribute to fussiness.

So how do you know if your child is deficient in zinc? There are tests that can be done to measure levels, but there are also telltale signs to look for in their symptoms and diet. Some of the symptoms of low zinc include:

Kids who are picky about animal products and wholegrains but eat sugary foods and processed carbohydrates are likely to become deficient. Zinc is found in foods such as red meat, fish and seafood, wholegrains, nuts and seeds. So if they’re not consuming these foods regularly, they are at a high risk of deficiency.

You can add a dose of zinc into their food by grinding up pumpkin seeds and sprinkling over cereal. But if they are deficient to the point of fussy eating, they’re likely to need a supplement. Your best option is working with a health practitioner to suggest a good brand and dose for your child’s needs.

Iron & Vitamin B12

These two nutrients are closely linked. In many cases, if a child is deficient in one, they will be in the other as well. It can take a while to pick up iron and B12 deficiency in children. Some of the symptoms of low iron and/or B12 can include:

  • Pale appearance
  • Fatigue and lethargy
  • Low stamina – they’re more likely to be tired after exercise
  • Feeling weak
  • Dizziness

If you’re concerned that your child might be deficient, you can do a blood test to confirm it. When kids have low iron and B12 levels, they’ll often need a supplement. If you want to explore supplementation, it’s best to work with a practitioner.

Iron is found mostly in red meat and green leafy vegetables. Vitamin B12 is found in animal products such as red meat, fish, chicken and eggs. This means that vegetarian children or those that dislike animal products are at a higher risk of being deficient. Low levels of these two nutrients can reduce appetite and lead to fussy eating.

Digestive issues

Any kind of digestive problem or imbalance can cause fussy eating. A tummy that works well and is comfortable to put food into is a hungry tummy! But a tummy that is painful or uncomfortable can lead to fussy tendencies.

The microbiome – the balance of bacteria in the gut – can impact on every aspect of health, including appetite and food preferences. I have seen time and time again in clinic. Improving gut health can help kids be more receptive to healthy foods and support a healthy appetite.

There are many factors that can affect a child’s microbiome. The most common include antibiotic use, a diet high in sugar and/or processed foods, pesticides, antibacterial cleaning products, hand sanitisers, and even stress. These can diminish the good bacteria and encourage the bad to overgrow. This can lead to cravings for sugar and carbs, bloating and constipation, which all drive fussy eating tendencies.

Another common problem for fussy eating is reflux in toddlers. They tend towards more bland foods that are less likely to cause symptoms, and associate other foods with their reflux. This association can continue into childhood and cause them to be picky with food.

Sensory issues

When the brain has difficulty processing information through the senses, it is considered a sensory issue. This is a common issue for kids with autism or ADHD, but it can also stand alone as sensory processing disorder.

If you think about it, eating involves every sense. You will see and taste the food, feel the texture, smell the fragrance, and hear the food being chewed in your mouth. Most of us won’t notice all of these, but kids with sensory issues find eating a challenge. For some, it’s like scraping nails down a chalkboard.

There are different issues that can arise, depending on the child. Some will hate lumpy foods, and some can’t mix food types together. Others will eat only hot or only cold foods. And some will prefer a texture, such as crunchy. Even strong smells and the sound of chewing food can trigger problems for some kids.

Some red flags for sensory issues include:

  • Gagging when they touch, taste or smell certain foods
  • Only eating specific textures
  • Disliking dirty, sandy or messy hands
  • Not tolerating tags on clothes
  • Not going through the oral stage as an infant where they put everything into the mouth, OR constantly putting everything into the mouth after 18 months old

Sensory issues are neurological in origin, so supporting the nervous system can help reduce symptoms. For best results, you’ll want to work with a health practitioner and an occupational therapist. The goal is to retrain their brain to let them know that things are ok. This can take time and patience, but it’s worth it!


Is fussy eating a problem for your kids? Grab my Fussy Kids mini-course here. You’ll learn how to help your little ones love healthy, fresh and nutritious food!












Nothing in this blog post constitutes or substitutes for professional or medical advice. Whilst Jessica Donovan (the Naturopath behind Natural Super Kids) is a registered health practitioner, she is not your health practitioner. Any health advice given by Jessica Donovan (or by any other person representing Natural Super Kids) is based on that person’s opinion and their general professional experience, but not your specific case. As such, you should always seek the advice of your own health professionals before acting on something that is recommended by Natural Super Kids. For our full disclaimer, please visit: