Why Children’s Diets Matter for their Mood and Behaviour – By Dr Alex Richardson

by | Jun 14, 2024 | Anxiety / Mood, Autism, Behaviour, Behaviour Therapy, Diet, Neurodevelopment, Sleep, Supplements, Wellbeing | 0 comments

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By Dr Alex Richardson, BAHons, D.Phil (Oxon), PCGE, FRSA

Adequate nutrition is absolutely fundamental to mental, as well as physical, health and wellbeing. Children’s diets have to provide not only the energy needed to power their brains and bodies, but also all the ‘raw materials’ needed to support their growth, development, ongoing maintenance and repair. Nutrition also affects gene expression and regulation, and influences all cell signalling throughout the brain and nervous system – so it is a key factor influencing mood, behaviour and ability to learn.

Standard management of Autism Spectrum Disorders, ADHD and related developmental or mental health conditions still ignores the possible contribution of nutrition and diet to the mood, behaviour or learning difficulties involved. Current UK treatment guidelines for health professionals essentially recommend against dietary or nutritional interventions for children with either ADHD or ASD,[1] advising instead that parents should simply follow standard ‘Healthy Eating guidelines’.[2]

However, the fact that diets of most typically developing children fail to meet these recommendations shows that feeding children well, and teaching them to make healthy choices for themselves even if they don’t have overt mood, learning or behaviour problems, is not a simple matter.

What’s more, many of the challenges that parents of children with ASD, ADHD and related conditions face on a daily basis actually involve their children’s preferences, feelings and behaviours around food, because feeding or eating disorders are thought to affect as many as 60-90% of ASD children,[3] and almost one third of those with ADHD.[4]

Highly selective and restricted eating habits and ‘food refusal’ are extremely common in ASD children, in many cases reflecting avoidant and fearful, rather than wilfully manipulative or oppositional behaviours.[5]  Either or both can make mealtimes – and any social occasions or outings that involve food – a major source of distress for all concerned.

“Many of the challenges that parents of children with ASD, ADHD and related conditions face on a daily basis acutally involve their children’s preferences, feelings, and behaviours around food”
Similar problems affect many children with ADHD – although overeating and binge eating (of favourite or ‘safe’ foods) are also common in both conditions. Notably, rates of obesity – which are high enough in general to be a major public health concern, are significantly elevated in both ADHD and ASD children. Some of the core features of these conditions – such as impulsivity, inattention or difficulties with emotional self-regulation leading to the use of food as comfort, or to ‘self-soothe’ may help to account for this, but both obesity and these neurodevelopmental conditions are highly complex and multifactorial.
Dealing with behavioural challenges and emotional upset over food, whether this involves food refusal, excessive cravings for unhealthy foods, or both is made even harder by the ‘vicious spiral’ that can develop if children’s diets are not healthy and well-balanced. It is a basic fact that poor nutrition compromises brain development and function – as well as physical health.

National diet and nutrition surveys[6] show that many children from the UK general population fail to obtain even minimum levels of one or more nutrients known to be essential for healthy brain development and function. Deficiencies of the long-chain omega-3 fats (found in fish and seafood, and vital to the normal structure and function of the brain and nervous system) are widespread, and associated with symptoms of ADHD, ASD, anxiety, depression, aggression and self-harm – as well as with physical health conditions which co-occur with ASD in particular at very high rates – such as allergies and immune disorders, and gastro-intestinal symptoms.  Learn more about omega-3s in our blog article: 

Vitamin D deficiencies are also common in all children – but have repeatedly been linked with autism, ADHD, depression and related conditions, and with poorer motor, language and cognitive development in the general population. Other ‘key brain nutrients’ frequently lacking from children’s diets in general include iodine, iron, zinc, Vitamins B12, B6 and folate (B9) and Vitamin A, as well as choline, selenium and magnesium. 

Receive specialised guidance from one of our nutritionists who specialises in micronutrients:  

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Clinical and population studies show that dietary and tissue deficiencies in any essential micronutrients are more common in children with behavioural problems like ADHD or ASD than matched controls – although how much this reflects poor dietary intakes, versus constitutional metabolic issues or other factors is unknown (and likely in any case to vary between individuals). Detailed US studies from a leading clinical centre have shown multiple essential micronutrient deficiencies in the blood of ASD children versus controls. Importantly, they have also shown that a comprehensive program of supplementation and dietary changes can not only improve nutritional status, but also general health, as well as mood and behaviour, in such children.[7]
View our list of supplements that may benefit individuals who are struggling with mood and behaviour issues:
Supplements for mental wellbeing
Turning to ‘macronutrients’ – compared with W.H.O and other official recommendations, most children consume far too much sugar, and far too little dietary fibre – and again this is particularly true of children ‘on the spectrum’. Either an excess of ‘free’ sugars, or a lack of dietary fibre alone will impair the balance and diversity of gut microbes – now known to have a powerful influence not just on gut and immune health, but also on brain function – and the combination of the two is particularly damaging.
‘Gut dysbiosis’ – an unhealthy balance of gut microbes – can directly increase stress, anxiety and problems with emotional regulation, and vice-versa.[8] It is also extremely common in children with ASD – whose food preferences and diets almost always include an exaggeration of the tendencies of typically developing children to favour the high-sugar, low-fibre, energy-rich and nutrient poor foods and drinks that now dominate most modern, western-type diets.  Learn more about gut dysbiosis in our blog article:
Almost all of the nutritional deficiencies and imbalances highlighted here reflect the very high intakes of so-called ultra-processed foods (UPF) – made from highly refined ingredients, using industrial processes, and characterised by the presence of usually multiple synthetic additives. Some of these additives – most notably, some artificial food colourings – have been shown – via rigorous randomised, double-blind, placebo-controlled trials to be capable of causing mood, behaviour and/or cognitive problems in children both with, or without pre-existing behaviour problems.
Learn more about the effects of additives and preservatives in our blog article:

High UPF consumption is robustly linked with – and has been shown to predict a wide range of chronic mental, as well as physical health problems. Furthermore, a recent rigorously controlled human clinical trial showed that a UPF diet caused overeating to the extent of 500 calories a day, and almost a kilo of weight gain in just two weeks, compared with a nutritionally matched diet of minimally processed foods.[9]  And yet these foods make up around two thirds of typical children’s diets in the UK, and are almost always the foods most favoured – or craved – by children with ASD, ADHD and related conditions.  Gain further knowledge about the effects that sugr has on behaviour in our blog article:  

All of the different issues noted above illustrate why it is not helpful for parents to believe anyone who tells them that food and diet are ‘not relevant’ to autism / ADHD / anxiety / depression or any other condition affecting a child’s mental health and wellbeing. Basic biochemistry, and abundant evidence from observational, experimental and clinical trial evidence shows that nutrition and diet can affect:

  • the mood and behaviour problems associated with ASD, ADHD and related conditions – but which also affect other children to varying degrees, and
  • many of the physical health problems that co-occur with these conditions at significantly elevated rates – reflecting the established links between gut, immune system and brain health.
Physical health conditions such as infection or chronic systemic inflammation can significantly increase needs for many nutrients (as can many common medications). Gut inflammation or dysbiosis can also compromise both nutrient absorption and digestion, and the ‘gut-brain axis’ refers to the very stong connections between gut and brain health. So it is notable that the prevalence of GI disorders in ASD children is five times that of matched controls,[10] and that gut pain or other digestive symptoms are also the most common co-occuring physical complaint in children with ADHD.[11]

Gain insight into your digestive system and potential problems that could lead to behavioral and mood-related issues in our blog article:

Importantly, a focus on co-occurring physical conditions and symptoms are the most likely way that parents may be able to get an evaluation of the nutritional status of their child with ASD, ADHD or similar conditions via public, rather than private health services – but often only if they push for a specialist referral.  Most health professionals still lack anything more than minimal education and training in nutrition generally, and pharmaceutical or behavioural treatments are usually first-line options in treatment guidelines for most physical complaints (GI disorders can be an exception).
The current lack of specific guidelines for nutritional or dietary management of developmental or mental conditions seems unlikely to change soon, as this reflects the emphasis placed on evidence from ‘controlled clinical trials’.  The relative lack of such trials in turn reflects the very serious limitations, obstacles and difficulties in carrying out such research with respect to both ‘nutrition’, and ‘neurodevelopmental or psychiatric conditions’, let alone the links between the two.
In reality, all of these ‘conditions’ actually have no objective markers, so the diagnostic labels used are purely descriptive. This means that any ‘study population’ so defined will be highly heterogeneous (including with respect to their nutritional needs, and any food sensitivities). With respect to ‘nutrition’ – we actually eat foods and diets, not nutrients – and those involve highly complex combinations of numerous different nutrients and other substances, such as dietary fibre – all of which work synergistically. But trials of real foods or diets are extremely difficult and expensive carry out for any length of time under double-blind conditions, while many nutritional influences operate over very long time-scales and in the case of early life nutrition, they are literally lifelong.
With respect to causal – rather than simply correlational – evidence that food affects behaviour, some nutritional and dietary interventions do actually have good evidence from controlled clinical trials, showing that these can significantly benefit mood, behaviour, sleep and/or aspects of learning in at least some of the many children who have problems in these areas. They are also too numerous to cover in this introductory overview (although references and articles on each can be found on the FAB Research website), but they can broadly be grouped under six main areas:

1. Negative effects of certain food additives on children’s behaviour

2. Multivitamins and minerals for general intelligence in children

3. Vitamins and minerals (with or without fatty acids) for antisocial behaviour in children and adolescents

4. Vitamins and minerals (with or without fatty acids) for ADHD in children and or adolescents

5. Omega-3 (+/- some omega-6) long chain polyunsaturated fatty acids for behaviour and learning in children with ADHD, ASD or related neurodevelopmental conditions.

Finally, getting any child to eat a ‘healthy, well-balanced diet’ is difficult enough; and for children with ASD, ADHD or related conditions, the associated mood, behaviour and attentional problems associated with these conditions make it extremely challenging.  So parents need more information and support; and more professionals need education and training on practical ways to help them. Basic evaluation and assessment of diet and nutrition as standard practice is needed, and where required, appropriate supplementation to cover important ‘nutrient gaps’
If you require additonal guidance or personalised support, schedule an appointment with one of our registered nutritionists:
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References

 

[1] NICE Guidelines for ADHD and ASD.

[2] NHS Eatwell Guide

[3] Ledford JR, Gast DL. Feeding problems in children with autism spectrum disorders: A review. Focus Autism Other Dev Disabil. 2006;21(3):153-166

[4] Jahrami et al, 2021.  The risk of eating disorders among children and adolescents with attention deficit hyperactivity disorder: Results of a matched cohort study. International Journal of Pediatric and Adolescent Medicine.

[5] ARFID – FAB links

[6] The National Diet and Nutrition Survey, 2017, HMSO

[7] Adams et al, 2018 Comprehensive Nutritional and Dietary Intervention for Autism Spectrum Disorder-A Randomized, Controlled 12-Month Trial

[8] Mayer et al, 2014. – Gut Microbes and the Brain: Paradigm Shift in Neuroscience. J Neurosci 34(46):15490-96.

[9] Hall et al, 2019 – Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab. 30(1) 67-77.e3

[10] McElhanon BO, McCracken C, Karpen S, Sharp WG. Gastrointestinal Symptoms in Autism Spectrum Disorder: A Meta-analysis. Pediatrics. 2014 May 1;133(5):872–83.

[11] Jameson ND, Sheppard BK, Lateef TM, Vande Voort JL, He J-P, Merikangas KR. Medical Comorbidity of Attention-Deficit/Hyperactivity Disorder in US Adolescents. J Child Neurol. 2016 Oct 1;31(11):1282–9.

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Disclaimer:  The views and opinions expressed in this blog post are those of the author and do not necessarily reflect the official policy or position of any professional organization or guidelines. The information provided is for educational and informational purposes only and is not intended as a substitute for professional advice, diagnosis, or treatment. Always seek the advice of your therapist or other qualified health provider with any questions you may have regarding a medical or mental health condition.