The Hidden Link Between Nutrition and Social Behaviour in Early Childhood

Early childhood is a critical period for brain development and the formation of social skills. During this time, the foundation for lifelong health and behaviour is established, making proper nutrition essential. But did you know that poor nutrition can significantly impact not only cognitive abilities but also social interactions in young children? A groundbreaking study explored this very connection, seeking to determine whether inadequate nutrition in early childhood affects social functioning and whether this impact is linked to neurocognitive ability.

How Nutrition Influences Behaviour in Young Children

The study followed nearly 1,600 three-year-old children, assessing them for key indicators of malnutrition, including:

• Sparse or thin hair – a sign of protein deficiency

• Angular stomatitis – linked to vitamin B2 and B3 deficiencies

• Hair dyspigmentation – another marker of protein deficiency

• Anaemia – measured through blood haemoglobin levels

To account for environmental and social factors, researchers also considered variables such as parental education, single-parent status, family size, and household conditions.

Measuring Cognitive and Social Development

To gauge cognitive function, the researchers used the Boehm Test of Basic Concepts – Preschool Version. Social behaviours were then observed in a controlled setting, focusing on:

• Exploratory play with toys

• Verbal interactions with researchers

• Friendliness towards assessors

• Active social engagement with peers

The Key Findings: Nutrition, Brain Development, and Social Skills

The results were striking. Children showing physical signs of malnutrition at age three demonstrated significantly lower levels of positive social interactions compared to their well-nourished peers.

Crucially, the study found that neurocognitive development played a major role in this relationship. Malnutrition first affects brain function, which in turn disrupts a child’s ability to develop positive social behaviours. In fact, cognitive impairment was responsible for over 55% of the link between malnutrition and poor social functioning.

One of the most important findings was the role of anaemia. Consistently associated with lower social scores, anaemia stood out as the most significant nutritional factor impacting early social development.

The Role of Key Nutrients in Brain and Social Development

Proper nutrition in early childhood ensures that the brain develops optimally, allowing children to interact, communicate, and form relationships effectively. Some essential nutrients that play a role in cognitive and social development include:

• Iron: Crucial for oxygen transport in the blood and brain development.

  • Found in: Lean meats, eggs, beans, lentils, fortified cereals, spinach, and other leafy greens.

• Omega-3 Fatty Acids: Support brain function, memory, and emotional regulation.

  • Found in: Fatty fish (salmon, sardines, mackerel), flaxseeds, chia seeds, walnuts, and algae-based supplements.

• B Vitamins: Help with energy production and neurotransmitter function, impacting mood and behaviour.

  • Found in: Whole grains, eggs, dairy, meat, leafy greens, and legumes.

• Zinc: Supports neural communication and immune function, playing a role in attention and behaviour.

  • Found in: Nuts, seeds, chickpeas, meat, dairy, and shellfish.

• Protein: Essential for overall growth, muscle development, and neurotransmitter production.

  • Found in: Lean meats, poultry, fish, tofu, beans, dairy, and eggs.

The Science Behind Protein and Neurotransmitters

Proteins are made up of amino acids, which serve as the building blocks for neurotransmitters—the chemical messengers that regulate mood, cognition, and social interactions. For example:

Serotonin (the "feel-good" neurotransmitter) is derived from the amino acid tryptophan, found in foods like turkey, eggs, and dairy.

Dopamine and norepinephrine, responsible for motivation, focus, and emotional regulation, are synthesised from the amino acid tyrosine, found in chicken, fish, and almonds.

GABA (gamma-aminobutyric acid), which promotes calmness and relaxation, is produced from glutamate, an amino acid found in whole grains, beans, and nuts.

Without adequate protein intake, the body may struggle to produce these neurotransmitters, leading to imbalances that affect mood, concentration, and social behaviour.

The Gut-Brain Connection: How Microbes Influence Mood and Behaviour

The gut is often referred to as the “second brain” because it contains millions of neurons that communicate with the central nervous system through the gut-brain axis. The microbiome—the diverse community of bacteria living in the gut—plays a crucial role in this process by influencing neurotransmitter production and inflammation levels.

Gut bacteria help produce serotonin, with over 90% of the body's serotonin synthesised in the gut.

A disrupted microbiome (due to a poor diet, processed foods, or antibiotic use) can contribute to anxiety, mood swings, and difficulty with social interactions.

Prebiotic and probiotic foods support a balanced gut microbiome, which in turn helps regulate emotions and behaviour.

Found in: Yogurt, kefir, sauerkraut, kimchi, bananas, garlic, onions, and whole grains.

How Blood Sugar Affects Behaviour and Focus

Fluctuations in blood sugar levels can cause irritability, difficulty concentrating, and mood swings in young children. A diet high in refined sugars and simple carbohydrates can lead to spikes and crashes, affecting behaviour and social interactions.

Why does this happen? When sugar is rapidly absorbed into the bloodstream, it causes a quick release of insulin, leading to a sharp drop in blood glucose. This "sugar crash" can make children feel fatigued, irritable, or anxious.

Balancing Blood Sugar: Meals should include protein, healthy fats, and fibre to maintain stable energy levels.

Found in: Whole grains, nuts, seeds, lean proteins, and healthy fats like avocado and olive oil.

The Impact of Food Additives and Processed Foods

Artificial colours, preservatives, and high sugar intake have been linked to hyperactivity and difficulty with emotional regulation in children. Processed foods often lack essential nutrients and can contribute to behavioural challenges.

Whole-Food Alternatives: Swap processed snacks for nutrient-dense whole foods.

Healthy swaps: Fresh fruit instead of candy, homemade popcorn instead of chips, and water instead of sugary drinks.

The Takeaway for Parents and Caregivers

This research highlights the profound impact of early nutrition on a child’s cognitive and social growth. Ensuring children receive adequate nutrients—particularly protein, iron, and omega-3 fatty acids—can support their brain development and ability to engage positively with the world around them.

For parents, caregivers, and educators, fostering healthy eating habits from an early age can give children the best start in life. By providing balanced meals and being mindful of key nutrients, we can support not only physical health but also the social and emotional well-being of our little ones.