Eating a varied diet is good for your health, but many people don't achieve this. Some autistic people have a restricted diet, eating only a limited range of food. Others may over-eat. This guide explores common issues, including pica, and ways you can help.
 

Problems to look out for 

There’s no need to be too concerned if the person is eating foods from each of the main food groups, and if a child, is growing well. Get advice if the person is: 

• accepting fewer than 20 foods 
• refusing all foods from one or more food groups 
• constipated – constipation can have a huge impact on appetite and may require medication 
• suffering from tooth decay as a result of their diet 
• losing weight or not growing well 
• gaining weight excessively 
• displaying behaviour, eg tiredness or pica (eating non-edible items) that might indicate a vitamin or mineral deficiency (eg iron deficiency anaemia) 
• missing school due to eating problems 
• coughing and choking while eating, or has recurrent chest infections, especially if they have developmental delay or physical disabilities 
• missing out on social opportunities, eg if they and their family can rarely go out due to the eating problems.
   

Finding the cause 

Start to take note of what is eaten and when. Sometimes, a food diary can be reassuring – you may in fact see that the person eats a wider range of foods than you originally thought. 

Here are some examples of what to include. 

• What time of the day did they eat? – 11.05 
• What did they eat? – Salt and vinegar crisps 
• Where did they eat? – In the living room 
• How much did they eat? – Two bags 
• Who was there? – Mum, brother 
• How did people around respond to the person eating the particular food? – Mum praised, brother had no reaction 
• Were there any environmental factors? – Radio was on in the background 

This could reveal some causes of the eating difficulties, whether over-eating or restricted eating. Try to work out whether it is the amount, type or range of food being eaten which is the core issue, and then what underlying problems, or sensory differences, may be involved.
 

General ways to help 

Communication 

With any approach, it is important that you communicate in a clear, consistent and calm way. 

A social story could help someone to understand why we eat and the function of food, eg: 

• food provides us with fuel/power, which enables us to do things we enjoy 
• eating food from all the food groups gives us energy 
•  missing out food groups can make us tired. 

Presenting information visually can also help. You could: 

• produce clear daily and/or weekly menus of foods – display the time of next meal in a prominent position 
• provide visual tools to help the person express and recognise their needs, feelings and preferences, such as stress scales, hunger and fullness scales, or happy/unhappy face pictures 
• have a food group chart, with a rule that they must have at least one food from each group each day. 

Try not to categorise foods into healthy and unhealthy, or good and bad. This can sometimes be taken too literally and can cause further problems. 

Try to be very specific when talking about food, or using pictures of food. For example, apples look and taste different, but we call them all apples. It's possible that the person likes Golden Delicious apples, and dislikes Braeburns, but is confused by you showing them a picture of a green apple, then bringing them a red one.

Rewards 

Using reward systems can be effective. However, avoid using a preferred food as a reward for trying a new or non-preferred food. It could make the preferred food even more attractive, and the new food appear like a chore. Also, ensure the emphasis of the reward is not just on eating a certain amount of a non-preferred food, but on tolerating new food being around, or tasting a new food. 

Exercise 

Encourage activities which involve movement and exercise. This can help with weight loss (if that's needed) and reducing stress, which may have contributed to over-eating or under-eating. If the person is reluctant, think about whether there could be any underlying reasons, eg difficulty with balance or socialising. 

Modelling 

It can be helpful to model the behaviour you're trying to encourage. This might mean that the whole family takes part in exercise, avoids snacking between meals, or follows a rule about eating something each day from each food group. 

Always speak to a GP, dietitian or other medical professional about the problems.
 

Common food issues and ways to address them 

Below are some examples of possible underlying problems – including sensory differences, illness and food presentation – and things you could try to address them. 

What works for one person may not work for another. 

Sensory experience 

Many autistic people experience sensory differences; being over or under-sensitive to sights, sounds, smells, tastes and textures. This can affect a person's experience of meals and relationship with food, and cause anxiety around food. 

Environment 

The person might find it too distracting to eat in a noisy canteen – find out if they could eat in a quiet room instead. The chair they sit on may be too hard – add a cushion. 

Playing some favourite music or a story in the background can be relaxing, distracting the person from the usual anxiety around eating. 

Food 

People who are very sensitive to smells and taste may prefer to eat quite bland food, and may find strong food smells overpowering. Under-sensitivity to taste or smell may mean the person prefers stronger flavours. Particular smells and flavours may be a source of intense pleasure. Some people might find the feeling of hard food, or sloppy food, unbearable. 

"I had a big problem with food. I liked to eat things that were bland and uncomplicated…I didn't want to try anything new…I was supersensitive to the texture of food, and I had to touch everything with my fingers to see how it felt before I could put it in my mouth." 

Baron and Baron (1992) in Attwood (1998), p.96 

Try modifying food to improve the sensory experience, for example by puréeing, and introduce a new food or textures in small steps, for a gradual desensitisation. 

First let the person just look at it, then touch it, then invite them to put the food on their plate, then smell it, lick it, put it into their mouth, bite it, chew it, and swallow it. Try not to react negatively to food being spat out. This is helping them to become comfortable with different foods being in and around their mouth. 

These steps could take months to complete. Try to see the goal as learning about and being comfortable around different foods, rather than getting them to eat all of the different foods presented. 

Discomfort and illness 

Physical pain and discomfort can affect how a person eats. Gut pain could cause a person to over-eat for comfort. Constipation can dampen appetite. Heartburn can stop someone wanting to continue to eat. Toothache and mouth ulcers can make someone reluctant to put things in their mouth. Some medication can affect appetite (eg Ritalin) or cause stomach upsets (eg antibiotics). A bloated intestine could cause a person to feel full when in fact they aren't. 

Support the person to communicate physical pain or discomfort, eg by using a visual stress scale, PECS (Picture Exchange Communication System), pictures of body parts, symbols for symptoms, or pain scales, pain charts or apps. 

Food presentation 

Attention to detail, and difficulty with change, is characteristic of autistic people. The way the food is presented or positioned on the plate, or the food's packaging, may dictate whether it is eaten or not. 

Has the positioning of the food on the plate been altered? Is the food over- or undercooked? Are there 'bits' on the food? Has the packaging changed? Is the logo a different colour? Is the box damaged? Have you bought a different brand? 

Social considerations 

Some people eat better in the company of their family or peers. They may be more willing to try new foods if they see other people trying the same food and enjoying it. 

For others, the social nature of mealtimes can be stressful. They might be more relaxed, and eat more volume or variety, if they ate alone in another room. 

If a meal is not going to be at home, prepare the person in advance by telling them who will be there, who will they be sitting with or next to, what people might talk about, and what they could say to start a conversation. 

Obsessions, special interests and routines 

Many autistic people have obsessions. If certain foods, or calorie counting, is an obsession, this could lead to over-eating, under-eating or a rigid diet. 

But obsessions, or special interests, can also prove helpful. 

You could try to channel an obsession with eating, or with weight loss, into something positive such as cooking and writing recipes. You could use a special interest to encourage them to eat more volume or variety, eg by eating from a Thomas the Tank Engine plate, cutting food into rocket shapes, or exploring foods from the country or region of their favourite singer or sports team. 

Many autistic people rely on routine and sameness. To eat well, they may need to have meals at the same time every day, be seated in the same position at the table, or always use the same plate or cutlery. 

This need for sameness could also explain a person's preference for processed foods. Processed foods are predictable, designed to look and taste the same each time. In contrast, there will always be natural variation in fresh food. Introduce new foods or textures in small steps. 

Coping strategy 

Sometimes, what appears as an obsession is in fact a coping strategy. Some autistic people say the world feels overwhelming and this can cause them considerable anxiety. Some people may over-eat, or avoid food, as a result of low self-esteem or anxiety. 

Try to minimise any stressful things the food diary has revealed, or encourage a different coping strategy, such as spending time on their special interest, or using the Brain in Hand digital self-management support system.  

Volume and variety 

If over-eating is still a problem after looking for causes and ways to address them, you could try: 

• reducing food portions, and using a smaller plate 
• showing them the empty saucepan, confirming verbally that the food has all gone 
• limiting access to food by keeping it out of reach, using locks or visuals such as no entry signs on fridges and cupboards, or not buying it at all in the case of snack foods like crisps and chocolate 
• setting rules relating to restaurants and food shops eg if you have a starter you cannot have a pudding 
• creating a food timetable, eg snacks at 10am, 3pm and 7pm, reducing the amount of food intake gradually 
• providing visual hunger and fullness scales to help with expressing and recognising cues. 

If under-eating is still a problem, you could try: 

• increasing food portions, and using a bigger plate 
• increasing the person's contact with food – making simple things such as sandwiches, fruit kebabs, little cakes or pizzas – to encourage positive associations 
• providing visual hunger and fullness scales to help with expressing and recognising cues 
• introducing a food book – place pictures or drawings of foods that the person likes in the front of the book, and those they don't at the back. As they try new food and expand their diet, the pictures can be gradually moved forward in the book. 

Pica 

Pica refers to eating or mouthing non-edible items, such as stones, dirt, metal, faeces. 

The reason a person on the autism spectrum might experience pica could be medical, dietary, sensory or behavioural and include: 

• not understanding which items are edible and inedible 
• seeking out sensory input – the texture or the taste of the item 
• relieving anxiety or stress 
• relieving pain or discomfort 
• displaying a symptom of iron deficiency  
• a continuing of infant mouthing behaviour, or a later occurrence of the mouthing phase 
• seeking attention 
• avoiding a demand. 

You could try to: 

• set up a sorting activity for the person to sort edible and inedible items 
• use PECS (Picture Exchange Communication System) to encourage the person to put appropriate items in their mouth and reward them 
• replace the inappropriate item with an appropriate alternative of a similar texture, eg a crunchy carrot stick, a chewy bracelet, popcorn, chewing gum 
• visit the GP or dentist to rule out any medical problems, oral pain or nutritional deficiencies, or to seek referral to an occupational therapist 
• increase the amount of structured activities in the person’s day 
• respond as neutrally as possible when the behaviour occurs, giving a firm 'no' with little eye contact, reinforcing it with a symbol 
• reduce demands placed on the person 
• distract and divert their attention. 

Other conditions 

Eating can be affected by a delay in physical development or low muscle tone. You could encourage activities that help to develop mouth and jaw movement such as using straws, blowing a whistle, blowing bubbles or using a toothbrush. 

Some people over-eat because they aren't able to know when they are full. This is a symptom of Prada-Willi syndrome, a rare genetic condition.
 

Professionals who could help 

Your GP might refer you to one or more of the following professionals or places. 

• Dentist: eating difficulties may result in, or be affected by, poor dental hygiene management or toothache. 
• Dietitian: they offer assessment and treatment of dietary related health problems such as constipation, allergies and intolerances as well as practical advice on eating problems, weight gain and weight loss. Ask your GP or consultant to refer you to an NHS dietitian or find a private dietitian. 
• Eating disorder clinic. 
• Clinical psychologist or psychiatrist: if the problem is thought to be psychological, these professionals can help with behaviour strategies. 
• Paediatrician: experts in child health issues who can help provide solutions to dietary issues and investigate underlying problems. 
• Occupational therapist (OT): may be able to offer advice on how you manage the situation at home. Use our Autism Services Directory to find an occupational therapist with autism experience, and other OTs in private practice. 
• Speech and language therapist (SALT): can advise on feeding issues and swallowing problems (dysphagia). Use our Autism Services Directory to find a speech and language therapist with autism experience, and other SALTS in private practice. 
• Counsellor: trained to talk through a variety of issues. Use our Autism Services Directory to find a counsellor with autism experience. 
   

Further information 

• Autism Services Directory
• Our autism and sensory experience online training module 
• Autism and eating challenges course
• beat, the UK's eating disorder charity 
• Can't eat won't eat: dietary difficulties and autistic spectrum disorders, Brenda Legge (2002) 
• The Eatwell Guide (NHS) 
• Food chaining - the proven 6-step plan to stop picky eating, solve feeding problems, and expand your child's diet, Cheri Fraker (2007) 
• Food…fun, healthy and safe, Books Beyond Words 
• We are grateful to Zoe Connor, for her advice on this page. 

Personal accounts 

• Autism and controlled eating  
• Autism and eating: compassion and connection  

Articles for professionals 

• Eating disorder or disordered eating?   
• Supporting autistic people with eating difficulties  
• Autism and eating issues: an interview with Dr Elizabeth Shea (video)
• Top five autism tips for professionals: eating issues