Children are what they eat. But how much impact does food have on your child's behaviour? Lucy Jolin reports

She's always tired. She can't sit still. The slightest irritation brings on a screaming fit. Could your child's diet be affecting her behaviour?

We all know the physical dangers of too much junk food, such as obesity and type two diabetes. But many experts now believe that constant consumption of ready meals and chicken nuggets can damage a child's mind as well as her body.

'Diet can affect cognitive ability and behaviour in children and adolescents,' concludes obesity specialist Dr France Bellisle in a study published in the British Journal of Nutrition,'Nutrient composition and meal pattern can exert immediate or long-term, beneficial or adverse effects.'

In practice, this means dehydrated, additive-fuelled children who can't concentrate, don't sleep properly, or can't sit still.

So when did the rot set in?
How has our childrens' diet got so bad?
'Before the 1970s, children ate what their parents ate,' says Suzannah Olivier, nutrition expert and author. 'But then manufacturers came up with the concept of 'children's food' like chicken nuggets. 'These foods are very cheaply produced. Consequently they're mostly salt, sugar, fat and additives, which disguise the fact that there are no proper ingredients.'

It's those substances that manufacturers add - weird and wonderful preparations like locust bean gum, caustic sulphite caramel or benzoic acid - which could be part of the problem. Although all food additives used in the UK must be approved, some are banned in other countries. Many have been linked to conditions such as asthma, rashes and hyperactivity. The Co-op supermarket chain recently banned 12 commonly used colourings from all its own-brand food.

One study of 277 three-year-olds by the Asthma and Allergy Research Centre found that drinking juice with artificial additives had a 'substantial effect' on the toddlers' sleep, ability to concentrate and general mood.

But it's not just additives that might affect the way our children behave. What's missing from their diets is also a factor. 'Iron deficiency anaemia can make people feel tired, irritable and less able to concentrate,' says Dr Joanne Lunn of the British Nutrition Foundation. 'In children, it can affect behaviour and development.'

Water boosts concentration
And with many schools accepting thousands of pounds a year from fizzy drinks companies in return for installing vending machines in their corridors, it's hardly surprising that most kids don't drink enough water.

'Low levels of dehydration can have an effect on mental performance,' says Dr Lunn. 'A study at Leeds University showed that children's ability to do arithmetic was impaired if they were between one to two per cent dehydrated. That's not even enough to cause feelings of thirst.'

So what's the solution? Go back to basics, says dietician Amanda Ursell. 'Eat like your grandparents,' she says. 'Cook plain food like porridge for breakfast, fruit and pitta bread for lunch, chicken and vegetables for dinner. Learn to understand food labels. And however busy you are, make sure your child eats regularly. Breakfast is particularly important. 'Research has shown that eating breakfast may improve children's problem solving abilities, memory, concentration levels, visual perception and creative thinking,' says Dr Lunn.

Olivier believes we should also teach our children more about the wonderful world of real food. 'Our children's tastebuds are blunted with salt and sugar,' she says. 'They should enjoy and appreciate real tastes and textures - not artificial ones.'

Brain foods for all the family

• Fish really is 'brain food'. Oily fish contains higher levels of omega-3 essential fatty acids than white fish. Common varieties include salmon, trout, fresh tuna, mackerel and herring
• Dairy products fortified with extra essential fatty acids are now available from supermarkets if your family's not keen on fish. Try Columbus eggs and Fresh Omega-3 milk
• All fruit and vegetables contain vitamins and minerals vital for good physical and mental health
• Nuts and seeds are rich in zinc, a mood-balancing mineral. Try sunflower, pumpkin, hemp and flax seeds

Omega-3 - what's the story?
Most children don't eat enough of the omega-3 essential fatty acids found in oily fish. We know that omega-3s are essential 'building blocks' for brain development, and several recent high-profile studies say a lack of omega-3s could cause bad behaviour.

Interim results from a trial of 60 children in Durham show that the behaviour of more than half the children involved has improved since they began to take supplements.

But Dr Lunn says more research is needed before we hail omega-3s as a miracle cure for bad behaviour. 'However, current guidelines state that women of reproductive age and girls should aim for one to two portions of oily fish per week. Those women past reproductive age, boys and men should have one to four portions every week,' she says. 'Supplements are an alternative source if you don't like oily fish.'

Find out more
Healthy Food for Happy Kids by Suzannah Olivier (Simon and Schuster, £10) or visit her website www.healthandnutrition.co uk.

What Are You Really Eating? by Amanda Ursell (Hay House, £5.99)

The Food Our Children Eat: How to Get Children to Like Good Food by Joanna Blythman (Fourth Estate,£8.99)

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