Adult ADHD – not ‘just a trend’

Rebecca Guerin highlights the need for dietitians to understand attention deficit hyperactivity disorder (ADHD).

We’ve all seen the headlines, the social media frenzy and increased conversations about attention deficit hyperactivity disorder (ADHD) in the UK over the past few years. Many of us will have noticed how this translates into our clinical practice.

It seems more and more patients are telling dietitians they have ADHD (or they suspect they have it) and, as dietitians, it can be difficult to know what to do with this information.

Like many dietitians, I started my career with only a brief introduction to neurodiverse conditions including ADHD, and as such I have had to do much of my learning ‘on the job’. I work with adults in a community mental health setting and I have been lucky to have some dedicated time in my current role to explore ADHD and diet.

The more time I spend researching this topic and discussing ADHD symptoms with my patients, the more I realise the huge impact ADHD can have on diet and engagement with healthcare professionals.

What is ADHD?

Attention deficit hyperactivity disorder is a neurodevelopmental condition characterised by traits of hyperactivity and inattention.

Most people diagnosed with ADHD experience a combination of inattentive and hyperactive/impulsive symptoms (50-75% of cases), while 20-30% experience primarily inattentive symptoms and around 15% experience primarily hyperactive symptoms.¹ There is a diagnosis rate of 3:1 male to female,¹ and some argue that ADHD is under diagnosed in females.²  There are also gender differences in the typical presentation of ADHD, with females typically displaying more inattentive and less hyperactive symptoms compared with males.¹

Some research suggests females with ADHD may internalise more of their symptoms, reporting a ‘busy brain’, becoming overwhelmed easily and experiencing low mood, anxiety and emotional lability.^{2, 3}

Table 1: Core symptoms of ADHD in adults

Adult prevalence of ADHD is currently estimated at 3–4% in the UK,¹ although some argue that ADHD is under-diagnosed in adults. ADHD UK estimates more than 80% of adults in the UK with ADHD are currently not diagnosed.⁴

Anecdotally, many people with ADHD also report symptoms such as emotional dysregulation, poor working memory and traits of people-pleasing and perfectionism. ADHD is also commonly associated with sensory differences,⁶ and many people with ADHD may consciously or unconsciously ‘mask’ their symptoms.⁵

While most of us can relate to some of the symptoms of ADHD at least some of the time, ADHD can only be diagnosed if symptoms are persistent and have direct negative impact on functioning.⁷

The charity ADHD UK states: "What makes ADHD different from normal distractibility and restlessness is the degree of features, the consistency of features across time and different settings, and the impairment caused by these features."⁸

Does ADHD affect diet?

Unfortunately, for both people with ADHD and the healthcare professionals supporting them, there is limited reliable information published around ADHD and diet. Additionally, there are several articles available recommending various diets to ‘cure’ ADHD, alongside companies advertising supplements with the aim to improve ADHD symptoms.

Currently, there are no concrete recommendations for a diet to improve symptoms of ADHD in adults, nor is there a sufficient evidence base to back up the numerous nutritional supplements on the market.⁹

We can say with some certainty, however, that people with ADHD are likely to follow an unhealthier eating pattern compared with the general population. This includes eating more processed foods, fewer fruits and vegetables and less protein.⁹

The importance of a balanced diet, exercise and healthy lifestyles is emphasised in NICE guidelines for ADHD and BNF prescribing guidelines for ADHD medication.^10,11

While this is important for the general health of people with ADHD, particularly because of the increased risks of obesity, diabetes and cardiovascular diseases in this population,^{12, 13, 14} there is not enough reliable evidence to suggest dietary modification could directly improve symptoms of ADHD.

Through my clinical experience of supporting people who have ADHD, I have seen many examples of how ADHD symptoms appear to affect diet. I have compiled some examples below that seem to come up frequently in my practice. Please note, this is not an exhaustive list and not intended as a substitute for thorough dietetic asessment exploring the barriers to achieving a healthy diet in individual patients.

Difficulty with meal planning

Many people with ADHD report feeling easily overwhelmed and unsure where to start with meal planning.

In my experience, this seems to be particularly prevalent for people with high perfectionism traits, who may aspire to ‘perfect’ diets, ‘perfect’ planning and potential for interpreting nutrition guidelines literally.

Dietitians can have a key role in supporting meal planning for people with ADHD. We can educate on flexible interpretation of nutrition guidelines and guide patients to start meal planning. In my experience, a flexible, semi-structured meal plan with some decisions made in advance can be helpful.

Discuss with the patient which days of the week they are busier and encourage them to plan quick meals on those days or, if time is less important than novelty, consider establishing a routine of certain cuisines on certain days.

By limiting the decisions the person must make each week, the task of meal planning can become less overwhelming and easier to engage with.

Forgetting to eat and drink

Rather than ‘attention deficit’, some argue that ADHD is characterised by difficulty regulating attention.¹⁵

Some people with ADHD also report experiencing hyperfocus, which is an intense form of concentration for a sustained period of time.16 Consequently, many with ADHD report forgetting to attend to their basic needs, including eating.

This can be especially difficult for people with sensory differences, which can include low sensitivity to hunger and thirst cues.

Some of the strategies I have found helpful with my patients include establishing regular mealtimes and backing this up with alarms or calendar reminders; using fluid tracker apps or water bottles with time goals; and keeping nourishing snacks within reach and eyeline during focused activity.

Distractions while cooking

Symptoms such as distractibility can mean forgetting about food while it is cooking. This may result in burned, unappetising food that can affect motivation and confidence to cook in the future.

This is one of the reasons why meals that can be cooked quickly are often easier for people with ADHD. Appliances that automatically switch off such as air fryers and microwaves can also be helpful, or setting timers for food when it is cooking.

For some people, however, more support with this is required to prevent risks such as fire during cooking. Occupational therapists really are the experts here and can have a key role in supporting people to safely and meaningfully participate in the functions of their daily life.

Cooking is ‘too much’

Many with ADHD report finding the idea of cooking overwhelming, uninteresting and difficult to motivate themselves to do.

Executive function challenges can make it difficult to start cooking and to manage the mess afterwards. This may lead to avoidance of cooking and relying more on convenience food and takeaways.

Simpler recipes using fewer ingredients and less cooking equipment can be helpful for reducing overwhelm with cooking.

Preparation can also be made simpler using tools such as pre-chopped and frozen vegetables, partly cooked food such as microwave rice, and balanced but convenient meals such as stir fry kits from supermarkets.

It can also be helpful to consider preparing food in advance of mealtimes, when the person feels most energetic or has more time to cook. This may mean preparing food early morning, late at night or batch cooking at the weekend to reheat at mealtimes.

Another strategy to increase motivation for cooking can be to combine the task with an enjoyable activity such as listening to music, podcasts or an audiobook. The key point is encouraging the person to work with their brain instead of against it.

Unplanned eating

People with ADHD commonly report unplanned eating. This may be because of inattentive symptoms that can lead them to feel bored more easily and seek pleasure from food. Impulsive symptoms can also make it harder for people with ADHD to think about food choices in advance, leading to them choosing highly rewarding foods and eating larger portions than intended.

In my experience, unplanned eating is more likely to happen when the person is not eating regularly and is experiencing more intense hunger. This can increase the sense of urgency to obtain food, affecting food choices and making portion control much harder.

Encourage regular meals and balanced snacks to prevent unplanned eating. Portion sizes of snack foods, e.g. crisps, chocolate, sweets, and so on, can be easier to manage with individual serving packs or decanting into another container, leaving the large packet in another room.

Dieting and changeable motivation

People with ADHD can often experience ‘all or nothing’ thinking styles. This, alongside difficulty regulating motivation and tendency towards impulsive decisions, can lead people to cycles of fad dieting.

As dietitians, we are well-placed to educate on the risks of fad diets as well as the benefits of gradual and sustainable changes. We can support people to make lifestyle changes they can follow long term and encourage people to re-engage with their goals if they lose motivation or slip up.

What about ADHD medication?

Drug treatment is recommended by NICE and BNF if lifestyle environmental modifications aiming to reduce the impact of ADHD symptoms in day-to-day life have not been sufficiently effective.^11,15 ADHD UK estimates only around 12.6% of people with ADHD in England have a prescription for ADHD medication,¹⁷ although it is estimated that medication is effective in up to 80% of patients with ADHD.18 Those who find the medication effective report improvements in ADHD symptoms and overall quality of life.¹⁸

The first-line medications recommended to treat ADHD in the UK are lisdexamfetamine mesylate and methylphenidate hydrochloride.¹⁰ Common or very common side effects of both medications include weight loss, reduced appetite, dry mouth and gastrointestinal symptoms including nausea and diarrhoea.^{19, 20}

If weight loss is a clinical concern, NICE guidelines¹⁰ recommend strategies including taking medication with or after food; consuming additional snacks early morning or late evening when medication effects have worn off; consuming high-calorie food of good nutritional value; and obtaining dietary advice. NICE guidelines¹⁰ also recommend considering trial periods of stopping medication depending on the balance of benefits and harms of medication.

In my practice, medication breaks have been considered, or withholding initial prescription of ADHD medication has been considered in the case of poor appetite, low weight or weight loss. Dietitians can use their skills and expertise to support these patients, preventing unintentional weight loss and nutritionally unbalanced diets that may result from poor appetite and overreliance on snacks rather than meals.

Are there other considerations for people with ADHD?

People with ADHD commonly experience poor mental health, including depression, anxiety and trauma.²¹ It is also common for people with ADHD to have another neurodevelopmental condition such as autism, dyslexia or dyscalculia.⁶ People with ADHD are also at increased risk of eating disorders such as bulimia nervosa, binge eating disorder and anorexia nervosa compared with the general population.^{22, 23}

The symptoms of ADHD and any co-occurring conditions can mean people with ADHD need reasonable adjustments to support their engagement with dietetic practice. ADHD, autism and mental health conditions can all class independently as disabilities under the Equality Act 2010.²⁴

As healthcare professionals registered with the HCPC, it is our duty to make reasonable adjustments for our patients where appropriate, ensuring we practise in an inclusive manner.²⁵ Reasonable adjustments may include altering the time, length or format of appointments (e.g. offering face-to-face rather than telephone appointments) to support engagement.²⁶

Another important consideration is building therapeutic relationships with patients. This allows the dietitian to more effectively explore barriers and formulate goals that are much more realistic, meaningful and effective for individual patients.

What about diagnosis?

In the UK, ADHD assessments and diagnoses typically occur within services specialising in ADHD, or with private psychiatrists experienced with ADHD. Patients in England seeking diagnostic assessment for ADHD should first speak to their GP (or NHS mental health service, if applicable) to request a referral to a diagnostic service.²⁷

Screening tools are often part of the diagnostic process for ADHD, and some people may wish to complete a screening tool to evaluate their own symptoms prior to requesting a specialist referral. However, online quizzes and tests are not all evidence based and may be used, for example, by social media pages to boost engagement with their content.

As with any health information, as dietitians we can support patients to access trustworthy information from sources such as the NHS, large organisations and charities including ADHD UK. We can support patients to complete evidence-based screening tools such as the ASRS v1.128 (Adult ADHD Self Report Scale) prior to the patient requesting diagnostic referral from their GP.

NHS trusts report variable waiting times for adult ADHD assessments, with some waiting lists as short as 12 weeks and others more than 10 years.²⁹ If referred to an NHS service, patients can ask how long the waiting list is in their local area, which can inform their decision to consider alternative options.

One of the options for many patients living in England is a referral to a private ADHD service paid for by the NHS through the Right to Choose scheme.²⁷ Waiting lists for these services are typically shorter than NHS services – between four and 24 weeks for some providers.³⁰ Some Right to Choose providers offer diagnosis only; others also offer medication treatment, often after a secondary waiting list.

Another option is for patients to access private services for diagnosis and possible treatment independently, paying for these services directly. Alongside concerns around the financial implications of a private diagnosis, some people worry that GPs and NHS mental health services may not recognise a diagnosis from a private service.

Advice for choosing a reliable private diagnostic service is available on the ADHD UK website.³¹

Take-home message

It is likely that we will continue to see a rise in patients with ADHD (or suspected ADHD) accessing dietetic services. These patients are likely to experience more barriers to maintaining a healthy balanced diet compared with neurotypical patients. As dietitians, it is our duty to adapt our approach to ensure people with ADHD are supported appropriately to access evidence-based nutrition advice.

References

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