Written by Toni Rudd, RD and reviewed by Talia Cecchele, RD
Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder which impacts a person's everyday life, in particular relationships, work or school performance, self-esteem and lifestyle choices. It is estimated that 5% of children and 3-4% of adults have ADHD (1).
Research has shown that there is a link between eating disorders (EDs) and ADHD, with similar traits presenting in both disorders and an increased risk of developing an eating disorder if a person is living with ADHD (2). This can lead to difficulty in receiving a diagnosis and receiving appropriately tailored treatment.
What is ADHD?
ADHD is a neurodevelopmental disorder which is diagnosed using the criteria set out in the Diagnostic Statistical Manual 5th edition (DSM-5). To meet diagnostic criteria, a person must present with a persistent pattern of six or more symptoms of:
Inattentiveness: difficulties with completing tasks, paying attention, and thinking.
Hyperactivity/Impulsiveness: high level of activity and/or excitement and acting on sudden ideas, thoughts or feelings
Combination of both (3)
The symptoms must interfere with functioning or development and be persistent for at least 6 months.
Symptoms of ADHD can include difficulties concentrating, organising, restlessness, forgetfulness and/or reduced attention span. This means it can be extremely difficult for the person with ADHD to plan, remember, control emotions and respond to situations. Sleep can also be hugely impacted (4).
There are no other tests or scans that can diagnose ADHD, and so a formal assessment must be completed by a specialist practitioner. Unfortunately, waiting lists in the UK can extend beyond 12 months to receive a formal assessment and diagnosis.
What is the link between EDs and ADHD?
It is very common to see ADHD coexist with disordered eating. Research suggests a person with ADHD is at an 11% higher risk of developing EDs such as binge eating disorder (BED) and bulimia nervosa (BN).
While there is no single cause for ADHD and eating disorders, often it is linked to certain biological and environmental factors such as family history, trauma and premature birth/low birth weight.
What are the similar traits of ADHD and eating disorders?
Increased exposure to restrictive diets: Some families with a child with ADHD or a person with ADHD can remove certain foods from their diet to improve their symptoms. Foods most commonly restricted include egg, soy and gluten (6). There is no current evidence that supports elimination diets to treat ADHD but this exposure to restrictive dieting overtime can develop into rigid thinking and food rules.
Irregular and erratic food intake: This might include skipping meals or not eating enough food because of low appetite or forgetfulness, especially when hyper-focused on tasks. Not eating enough food across the day can lead to weight loss, binge eating and eating past what feels comfortable. This might also be due to a lack of interest in food or finding the process of preparing meals and eating boring or more of a chore.
Difficulties with impulsive behaviours: Impulsivity traits are seen in both ADHD and eating disorders, particularly BED and BN. People with ADHD might struggle to resist the urge to binge, leading to feelings of guilt/shame and/or purge-type behaviours. Similarly, with exercise, both ADHD and eating disorders can develop a compulsive relationship with exercise
Reward deficiency syndrome: This highlights how difficult it can be for someone with ADHD to feel the response to dopamine due to the low levels in the brain. A dopamine rush might be felt after eating, or from the act of controlling food choices, such as in disordered eating or an eating disorder. The constant stimulation from eating might lead to someone then engaging in overeating or binge eating behaviours.
Medication considerations for ADHD
Medication is often prescribed to support someone with ADHD to help them in their everyday activities. These medications (both stimulant and non-stimulant) can come with side effects such as reduced appetite, abdominal pain, nausea and vomiting (4).
These side effects can interfere with a person's natural hunger and fullness signals, leading to a reduced appetite which can make it difficult to remember to eat. Meal planning can be difficult if there is a lack of routine in someone's life as spontaneity can be challenging. Both of these reasons can increase the risk of a person with ADHD not eating enough to nourish their body and mind in recovery.
It is not only restrictive eating that can present in ADHD, but many people also experience binge eating, for when the side effect of medication (reduced appetite) has worn off, or if there is a long period without eating, then binge eating can occur in the evening/middle of the night.
Read more in our separate blog about how this differs from Night Eating Syndrome.
Nutritional Considerations for ADHD and Eating Disorders
Make a mealtime routine and don’t wait for hunger cues:
Aim to eat 3 main meals and 2-3 snacks each day. It might help to set regular alarms or have reminders for eating if you are prone to forget or are usually distracted to avoid going long periods without food. This will help to establish your hunger cues and minimise erratic and impulsive eating. Get some guidance for free with our How To Build a Balanced Plate Guide.
Reduce decision overwhelm/fatigue:
If you struggle with decision-making and can get overwhelmed with too many choices when it comes to meal times. It will be helpful to plan your meals by writing a meal plan. Try to avoid planning a different meal every day and make the most of cooking larger portions at once so you can use leftovers to reduce time.
Reduce caffeine intake
There is some thought that caffeine can increase concentration, similar to ADHD medication. However, it is not currently supported to be used as an alternative to medication. If you have ADHD, you could be more susceptible to the side effects of caffeine with increased jitters, irritability, anxiety, stomach pains and headaches. A high intake of caffeine can also contribute to a reduced appetite.
Emotional and/or boredom eating management:
Understanding and learning the reasons why you turn to food to deal with emotions is really important to set up a plan. If it is linked to low dopamine levels, increasing ways to feel stimulated away from food is very important. This might include playing a game, gardening or drawing.
Sensory awareness around food
Having ADHD might make you more sensitive to certain smells, tastes and textures of foods. This can make certain foods more desirable than others for example, the crunchiness of crisps. But also, sensory issues can make some foods very off-putting. Having an awareness of what foods you prefer and don’t prefer might be helpful when writing a meal plan so you include the food you enjoy and prefer. It's important to note that these preferences can change over time.
Build a positive night routine to improve your sleep:
Not sleeping well or enough can have an impact on your diet and food choices the next day. Having a wind-down routine for sleeping can be helpful to improve the amount/quality of sleep you are getting. This could include reducing screen time, making the room dark and cosy and idea dumping in a notepad.
Need support with ADHD & an eating disorder?
Having ADHD and an eating disorder can be overwhelming and difficult to manage alone, especially if it has been going on for a long time. We offer 1:1 support at the TCN clinic to help you overcome food rules, find food freedom and kickstart your recovery. You can find out more about how we can support you here.
Toni Rudd
TCN Specialist Dietitian
Toni is passionate about supporting people to achieve a truly healthy relationship with food and body acceptance, by healing their relationship with food and body by establishing sustainable, health-promoting behaviours for life. Toni works for the TCN Clinic alongside her work as @thebingedietitian
Talia Cecchele Nutrition is a team of registered dietitians that specialise in eating disorder recovery, disordered eating, digestive issues and sports nutrition. We aim to bring balance back to nutrition, help you to break free from food rules and find food freedom. We offer virtual consultations and group programs so whether you are based in London, the United Kingdom or around the world we would love to support you. To enquire about a private consultation please fill out a contact form.
REFERENCES:
DSM-V, 2013. Feeding and Eating Disorders. [online] DSM Library. Available at: <https://doi.org/10.1176/appi.books.9780890425596.dsm10> [Accessed 14 August 2023]
Nazar, B. P., Bernardes, C., Peachey, G., Sergeant, J., Mattos, P., & Treasure, J. (2016). The risk of eating disorders comorbid with attention-deficit/hyperactivity disorder: A systematic review and meta-analysis. The International journal of eating disorders, 49(12), 1045-1057. https://doi.org/10.1002/eat.22643
ADHD UK. 2023. ADHD Incidence - Childhood and Adult ADHD incidence rates. [ONLINE] Available at: https://adhduk.co.uk/adhd-incidence/. [Accessed 03 August 2023].
NHS UK. 2023. Attention deficit hyperactivity disorder (ADHD) - NHS. [ONLINE] Available at: https://www.nhs.uk/conditions/attention-deficit-hyperactivity-disorder-adhd. [Accessed 03 August 2023]
Thapar et al (2011) What causes attention deficit hyperactivity disorder? Child and Adolescent Psychiatry Section, Department of Psychological Medicine and Neurology, Cardiff University, https://adc.bmj.com/content/97/3/260
Restriction and Elimination Diets in ADHD Treatment Joel T. Nigg, PhDa,* and Kathleen Holton, PhD, MPHb https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4322780/