Therapeutic fasting (Buchinger, F. X. Mayr)

1. Introduction

Version followed: medically supervised therapeutic fasting (Heilfasten) as set out in the guidelines of the Ärztegesellschaft Heilfasten und Ernährung (ÄGHE): first consensus version 2002 (Forsch Komplementmed 2002; 9: 189–198) and the expert-panel update by Wilhelmi de Toledo et al. 2013 (Forsch Komplementmed 20(6): 434–443, DOI 10.1159/000357602). The Buchinger method is described as the Buchinger Wilhelmi clinics publish it; F. X. Mayr therapy as the Internationale Gesellschaft der F.X. Mayr-Ärzte publishes it (Witasek, ed., Lehrbuch der F.X. Mayr-Medizin, Springer 2019). Statements on the guideline rest on the 2013 update's full text, published open access by Karger [source: Wilhelmi de Toledo et al. 2013, Karger full text], and its bibliographic record [source: MDC edoc record; ÄGHE literature page].

What it is. Therapeutic fasting is a medical procedure in which a person voluntarily goes without solid food for a limited period under medical supervision, followed by a planned, gradual return to eating. The 2013 update describes it as a structured therapy with a long European history, delivered in specialised fasting hospitals and in departments of integrative medicine [source: Wilhelmi de Toledo et al. 2013, abstract]. Two named traditions sit under this heading:

Buchinger fasting (after the physician Otto Buchinger) is the method of the Buchinger Wilhelmi clinics (Lake Constance). The clinic describes a voluntary period without food in which the body draws mainly on fat reserves, followed by a refeeding phase it calls regeneration, set inside a lifestyle programme of talks, coaching and seminars [source: Buchinger Wilhelmi, therapeutic fasting page].
F. X. Mayr therapy (Franz Xaver Mayr, 1875–1965, Austrian gastroenterologist) is a physician-led cure built on four principles, the "four S": Schonung (rest for the digestive system), Säuberung (cleansing), Schulung (re-education of eating behaviour) and Substitution (replacing what is lacking). It uses an individually set diet, practice of a regular eating rhythm, and a manual abdominal treatment given by the physician. It is delivered as an outpatient treatment or in certified facilities [source: DocCheck Flexikon, F.-X.-Mayr-Kur; Witasek 2019, publisher page].

Core idea of change, as the traditions state it. The clinics describe fasting as a biological stimulus that switches metabolism to fat-based fuel, with effects on weight, blood pressure, lipids and glucose regulation, and on physical and emotional well-being [source: Buchinger Wilhelmi indications page; PLoS ONE 2019 observational study, abstract]. The clinic also uses the phrase "deep cleansing" of cells and tissue, and Mayr therapy is described as "detoxifying" the body; these are the traditions' own concepts. Reference sources describe the detox framing and Mayr's health effects as scientifically disputed and not confirmed (DocCheck, as of 2014) [source: DocCheck Flexikon, Heilfasten; F.-X.-Mayr-Kur].

Evidence status (brief). The 2013 guideline reports the strongest evidence for chronic rheumatic diseases, with preliminary clinical and observational data for metabolic disease, pain syndromes, hypertension, chronic inflammatory and atopic disease and psychosomatic disorders [source: Wilhelmi de Toledo et al. 2013, abstract]. Fasting is not a treatment for cancer or any other physical disease; the clinic lists cancer only as an area "currently in research" [source: Buchinger Wilhelmi, therapeutic fasting page].

Who delivers it and the psychotherapist's place. The 2013 guideline states that all fasting interventions should be guided or accompanied by physicians or therapists trained and certified in fasting therapy [source: Wilhelmi de Toledo et al. 2013, abstract]. The ÄGHE runs further training and publishes lists of trained fasting leaders (Fastenleiter:innen) and medical practices [source: ÄGHE literature page, navigation]. In Austria, F. X. Mayr training leads to a diploma of the Austrian Medical Chamber (ÖÄK) [source: Witasek 2019, publisher page]. A psychotherapist does not prescribe, run or supervise a fast. This guide covers the method so that you can understand it, and sets out your own role: screening, referral, working with the supervising physician, monitoring mood, eating and body image, integrating the experience, and recognising harm [synthesis].

2. Framework

2.1 The medical course (as the sources describe it; for the therapist's understanding, not instruction)

Medical assessment and selection. At Buchinger Wilhelmi each guest is interviewed and examined by a doctor at the start of the stay, who decides whether fasting or an alternative nutritional programme suits them. Guests who are underweight, weak or exhausted, or who take strong or complex medication, receive supplements during the fast. The clinic does not treat drug or other dependencies, severe alcoholism, or eating disorders such as anorexia and bulimia, and offers non-fasting nutritional alternatives [source: Buchinger Wilhelmi, therapeutic fasting page]. The 2013 ÄGHE guideline lists as contraindications cachexia, anorexia nervosa and other eating disorders, uncontrolled hyperthyroidism, advanced cerebrovascular insufficiency or dementia, advanced liver or kidney insufficiency, and pregnancy and breastfeeding. It names further conditions (among them addictions, type 1 diabetes, psychotic disorders, severe or unstable coronary disease and cancer) in which a fast may proceed only under a physician experienced in fasting, and gives reasons for stopping a fast, such as non-compliance, significant arrhythmia or severe electrolyte disturbance. The history should cover eating disorders explicitly, and patients should be asked about medicines they may not have mentioned [source: Wilhelmi de Toledo et al. 2013, full text].
Preparation. The 2013 guideline describes a preparatory day of reduced eating with stimulants such as caffeine, alcohol and nicotine left out and some mental preparation, then bowel cleansing at the start of the fast, repeated during it, with milder options for people with a sensitive gut, low blood pressure, a history of headache or exhaustion [source: Wilhelmi de Toledo et al. 2013, full text]. General reference sources name a laxative salt (Glauber's salt) as the usual agent [source: DocCheck Flexikon, Heilfasten]. Described here as a fact about the method, not as an instruction.
The fast. Solid food is left out, depending on the variant, and the person stays under medical monitoring with a supporting programme (Buchinger Wilhelmi: talks, demonstrations, individual coaching, seminars on nutrition, medicine, psychosomatics, meditation and mindful habits) [source: Buchinger Wilhelmi, therapeutic fasting page]. The 2013 guideline limits intake on fasting days to fluids such as water, herbal tea, broths and juices, as the physician sets them, and frames the fast within a programme of individually adjusted activity, rest, relaxation methods (for example yoga, tai chi, progressive muscle relaxation), time for silence and meditation, group support, emotional support it calls "dietetics of the soul" (music, reading, nature, humour), health education, and behaviour-change work aimed at lasting change after the fast [source: Wilhelmi de Toledo et al. 2013, full text]. In Mayr therapy the corresponding phase is an individually set, gentle diet with practice of eating rhythm and the physician's abdominal treatment [source: DocCheck, F.-X.-Mayr-Kur].
Breaking the fast and refeeding. A gentle fast-breaking with small, slowly eaten portions of simple food, followed by build-up days with a gradual return to a light, mainly plant-based, fibre-rich diet [source: Wilhelmi de Toledo et al. 2013, full text; Buchinger Wilhelmi; DocCheck, Heilfasten]. This is the phase in which refeeding syndrome can occur in people at risk (see Harm account) [source: NHS Highland refeeding guideline].
After-care. The clinic offers a follow-up programme for maintaining changes at home and reports that many guests become highly motivated to change their lifestyle after a first fast [source: Buchinger Wilhelmi, therapeutic fasting page].

Lengths, intakes and schedules are set by the supervising physician for each person and are deliberately not given in this guide. Fasting lengths in published studies vary widely [source: PLoS ONE 2019, abstract].

Settings. Inpatient (specialised fasting clinic, hospital department of integrative medicine, certified Mayr facility) or outpatient with a qualified physician or certified fasting leader [source: Wilhelmi de Toledo et al. 2013; DocCheck, F.-X.-Mayr-Kur; ÄGHE page]. The 2013 guideline separates two forms. Fasting for healthy people (prevention) is shorter and non-medical, meant for people who are well, take no medication, are emotionally stable and decide for themselves; it is done at home, in groups or at resorts, guided by a trained fasting leader, with a fasting-experienced physician available in the background. Fasting therapy for illness is led by a physician trained in fasting therapy with a multidisciplinary team and medical monitoring, including blood tests and cardiac checks, as inpatient or outpatient treatment [source: Wilhelmi de Toledo et al. 2013, full text].

2.2 The psychotherapist's parallel track [synthesis]

Stage	Goal	Typical format	Move on when
A. Exploration and screening	Understand why the client wants to fast; screen for eating-disorder and other risk	1–2 ordinary sessions	Risk is low and the client agrees to medical assessment, or the plan is set aside
B. Referral and collaboration	Medical assessment by a qualified fasting physician; consent to share information	Letter or call with consent	Physician has assessed the client and the medical plan is clear
C. Accompaniment during the cure	Monitor mood, sleep, eating thoughts, body image; keep contact with the physician	Shorter check-ins, or a pause by agreement during a residential stay	The fast and refeeding are finished
D. Integration and after-care	Make sense of the experience; watch for relapse and rebound eating	1–3 sessions, then routine work	Eating and mood are stable and any warning signs have been followed up

If at any stage there are signs of an eating disorder, a medical warning sign, or a plan to fast without supervision, stop the track and move to Interventions 4.6–4.8 [synthesis].

3. Guiding principles

Medical supervision only. The guideline requires trained, certified physicians or therapists for every fasting intervention [source: Wilhelmi de Toledo et al. 2013, abstract]. In practice: you never help a client plan or carry out a fast; you route them to a qualified physician.
Screen for eating disorders first, every time. Leading clinics exclude anorexia and bulimia [source: Buchinger Wilhelmi]. In practice: ask about current and past eating problems before you discuss fasting at all [synthesis].
Stay inside your competence. In practice: no advice on medicines, intakes, lengths, laxatives or enemas; any question about medication goes to the prescriber [synthesis].
Attribute the theories. "Detox", "cleansing" and Mayr's gut-centred account are the traditions' concepts and are contested [source: DocCheck Flexikon]. In practice: say "the clinic describes it as…" rather than endorsing it.
No claims to treat physical disease. In practice: if a client hopes fasting will cure cancer or another illness, name this gently and send them back to their treating doctor [source: Buchinger Wilhelmi lists cancer only as research; synthesis].
Collaboration with consent. In practice: get written consent to talk with the fasting physician and the GP, and agree what you will each watch for [synthesis].
Weight-neutral stance. In practice: no weight targets or praise of weight loss in sessions; keep attention on well-being and function [synthesis].
Consent and trauma awareness for touch. Mayr therapy includes a manual abdominal treatment by the physician [source: DocCheck, F.-X.-Mayr-Kur]. In practice: help clients with trauma histories prepare to give or withhold consent, and to stop treatment at any moment [synthesis].
Watch the refeeding phase. Refeeding is the medically riskiest phase for people at risk [source: NHS Highland, citing NICE CG32]. In practice: ask in particular about the days after the fast ends.
Respect the client's choice, inside safety limits. In practice: a medically assessed fast in a qualified setting is the client's decision; your job is to make it informed, not to forbid or to promote [synthesis].

4. Intervention inventory

The inventory has two parts. Part A describes the components of the cure as the clinics and reference sources publish them, so you know what your client will meet; these are delivered by physicians and certified fasting staff, never by you. Part B gives the psychotherapist's own interventions, which are [synthesis] unless a source is named: the sources describe the medical method, not a psychotherapy protocol.

Part A. Components of the cure (description only)

A1. Medical intake assessment

Purpose: decide whether fasting, a modified programme or no fasting suits the person [source: Buchinger Wilhelmi].
What happens: interview and physical examination by a doctor at the start of the stay; supplements for people who are underweight, weak, exhausted or on strong or complex medication; exclusion of people with dependencies, severe alcoholism, anorexia or bulimia [source: Buchinger Wilhelmi]. Blood tests before and after the fast were part of the 2019 observational study [source: PLoS ONE 2019, abstract].
Example language (illustrative): "The doctor there will examine you and decide with you whether fasting is right. Would it help to write down your questions and your medicines list for that appointment?"
Watch for: a client who plans to leave out eating-disorder history or medicines at intake; encourage full disclosure [synthesis].

A2. Preparation and bowel emptying

Purpose (as the tradition states it): prepare the body for the fast [source: DocCheck Flexikon, Heilfasten].
What happens: a phase of reduced eating, then bowel emptying, usually with a laxative salt, under the clinic's direction [source: DocCheck Flexikon, Heilfasten]. Not to be done by the client on their own initiative [synthesis].
Example language (illustrative): "The clinic will guide that part. If laxatives have ever been part of how you managed weight or feelings, that is important to tell them and me."
Watch for: past laxative misuse or purging; any excitement about "emptying" or "cleaning out" that sounds like purging relief [synthesis].

A3. The fasting phase with its supporting programme (Buchinger)

Purpose: the clinic's therapeutic stimulus, in a programme of talks, demonstrations, individual coaching and seminars on nutrition, medicine, psychosomatics, meditation and mindful habits [source: Buchinger Wilhelmi].
What happens: no solid food for a period set by the physician; daily recording of clinical measures, adverse effects and well-being in the clinic's research setting [source: PLoS ONE 2019, abstract].
Example language (illustrative): "Many people find the group talks and quiet time as important as the fasting itself. What would you like to use that space for?"
Watch for: low mood, irritability, poor sleep, preoccupation with food or body, feeling faint; these go to the clinic staff [synthesis].

A4. Mayr therapy: rest, cleansing, re-education, substitution

Purpose: the four principles of F. X. Mayr medicine [source: Witasek 2019, publisher page; DocCheck].
What happens: an individually set diet, training of a regular eating rhythm (Schulung), the physician's manual abdominal treatment, and replacement of deficiencies (Substitution), as an outpatient or in a certified facility [source: DocCheck, F.-X.-Mayr-Kur]. Mayr diagnostics and the individual diet are set by the Mayr physician and are not described here.
Example language (illustrative): "The Mayr doctor will look at how you eat as well as what you eat. What do you notice about your own eating pace and rhythm?"
Watch for: rigid rule-keeping about "right" eating, guilt after breaking a rule, or eating rules spreading into social life: possible orthorexic or restrictive patterns [synthesis].

A5. Mayr manual abdominal treatment (touch)

Purpose (as the tradition states it): a massage-like abdominal treatment by the physician, said to support cleansing and lymph flow [source: DocCheck, F.-X.-Mayr-Kur]; this rationale is the tradition's own and is not established [source: DocCheck].
What happens: hands-on treatment of the abdomen by the Mayr physician [source: DocCheck].
Your role: preparation for consent, not delivery. Explicit consent before and during any touch, the right to stop at any moment, the option of a chaperone, and touch that is never sexual [synthesis, consistent with general touch ethics].
Example language (illustrative): "Abdominal touch can bring up strong feelings, especially if your body has been touched without your agreement before. You can ask the doctor to explain each step, to have someone with you, or to stop at any point."
Watch for: freezing, dissociation, shame or panic before or after treatment; signs that consent was not freely given [synthesis].

A6. Breaking the fast, refeeding and after-care

Purpose: gradual return to normal meals, which the clinic calls regeneration, and a follow-up programme at home [source: Buchinger Wilhelmi].
Medical risk: this is the phase in which refeeding syndrome occurs in people at risk; NICE-based guidance names prolonged fasting and anorexia nervosa among risk groups [source: NHS Highland, citing NICE CG32].
Example language (illustrative): "How has eating been since the fast ended? Any urges to eat a lot at once, or to keep restricting?"
Watch for: binge urges, continued restriction, plans to fast again soon, and any physical warning signs (see 4.9) [synthesis].

Part B. The psychotherapist's interventions [synthesis unless a source is named]

4.1 Exploring the wish to fast

Purpose: understand what the client hopes fasting will do (health, a reset, spiritual meaning, control, weight, punishment) before any referral.
Steps: (1) Ask open questions about where the idea came from and what they hope for. (2) Reflect back the hopes in their words. (3) Ask what it would mean if the fast did not deliver this. (4) Note any hopes linked to weight, shape, guilt, "earning" food or getting rid of feelings. (5) Agree that a medical assessment is the next step if they still wish to go ahead.
Example language (illustrative): "What draws you to fasting right now? … And if you came back from it feeling much the same, what would that be like?"
Watch for: fasting framed as punishment, purification after eating, a response to a recent loss or crisis, or a way to get a body "under control". Working well: the client can name realistic aims and is open to medical advice.

4.2 Eating-disorder and risk screening

Purpose: identify people for whom fasting is likely to be harmful. Leading clinics exclude anorexia and bulimia [source: Buchinger Wilhelmi]; the 2013 guideline makes anorexia nervosa and other eating disorders a contraindication both to fasting therapy and to fasting for healthy people, and notes that the neuroendocrine effects of fasting might reinforce disordered eating [source: Wilhelmi de Toledo et al. 2013, full text].
Steps: (1) Ask about current and past eating problems: restriction, bingeing, vomiting, laxative or diuretic use, compulsive exercise, avoidant or very selective eating (ARFID), and rigid "healthy eating" rules (orthorexia). (2) If you are trained in it, use a brief screener such as the SCOFF questionnaire: five yes/no questions developed at St George's Hospital Medical School, where two or more "yes" answers point to possible anorexia or bulimia nervosa and call for assessment by a qualified health professional; a positive result is not a diagnosis [source: Morgan, Reid & Lacey 1999, as reproduced on NHS Scotland Right Decisions]. Do not treat a negative screen as clearance [synthesis]. (3) Ask about pregnancy or breastfeeding, diabetes and glucose-lowering medicines, underweight or recent weight loss, alcohol use, other medical conditions and age (older adults; adolescents are not candidates for self-chosen fasting through you). (4) Ask about mood, self-harm and suicidal thoughts, using your service's standard risk assessment. (5) Summarise and decide: proceed to referral (4.3), or pause and assess for an eating disorder (4.6).
Example language (illustrative): "Before we go further, I ask everyone the same questions about eating, because fasting affects some people very differently. Has food or weight ever felt like it was taking over?"
Watch for: minimising, a sudden change of subject, or a history the client did not plan to tell the clinic. Working well: an honest picture that you can pass on, with consent.

4.3 Medical referral and collaboration

Purpose: make sure fasting happens only under a physician or certified fasting therapist, as the guideline requires [source: Wilhelmi de Toledo et al. 2013, abstract].
Steps: (1) Explain that you do not advise on fasting itself or on medicines. (2) Encourage the client to see their GP or prescriber about all medicines before any fast. (3) Point them to a qualified provider (ÄGHE lists of fasting physicians and trained fasting leaders; certified Mayr physicians) [source: ÄGHE page; Witasek 2019]. (4) With written consent, send a brief letter: your role, relevant history (eating, mood, trauma, risk), what you will watch for, and how to reach you. (5) Agree with the client what will be shared both ways.
Example language (illustrative): "Questions about your tablets need to go to the doctor who prescribes them; please don't change anything on your own. Can I write to the fasting doctor so we're working together?"
Watch for: reluctance to involve any doctor, choice of an unqualified retreat, or a plan to change medicines alone. Working well: named physician, consent in place, plan agreed.

4.4 Preparing the client psychologically

Purpose: set realistic expectations and plan for distress during a residential or outpatient cure.
Steps: (1) Discuss what may be hard: hunger, irritability, tiredness, low mood, being away from routine, group settings. (2) Make a short coping plan using skills the client already has. (3) Prepare for touch-based parts (A5). (4) Agree whether you will pause sessions or keep brief contact, and who they will tell if they feel unwell.
Example language (illustrative): "If on day two you feel low or snappy, what would help, and who on the clinic team would you tell?"
Watch for: expectations of dramatic transformation; plans to fast for longer than the doctor advises. Working well: the client has a plan and knows when to speak to staff.

4.5 Accompaniment and monitoring during the cure

Purpose: notice psychological changes and pass physical concerns to the physician.
Steps: (1) Keep check-ins short and focused: mood, sleep, anxiety, thoughts about food and body, contact with staff. (2) Ask directly about feeling faint, confused, very weak or having palpitations, and if present direct them to clinic staff or urgent care at once (4.9). (3) Record and, with consent, share relevant changes with the physician.
Example language (illustrative): "How have mood and sleep been? Any dizziness, confusion or heart racing? If so, that's one for the doctor today, not for our next session."
Watch for: rising low mood, agitation, food preoccupation, or secrecy about eating. Working well: stable mood and open contact with the clinic team.

4.6 Responding to signs of an eating disorder

Purpose: move from a fasting conversation to assessment and treatment of a possible eating disorder.
Steps: (1) Name your concern without judgement. (2) Advise against fasting while this is assessed. (3) Refer to the GP and to specialist eating-disorder services according to local pathways; involve medical monitoring where weight, intake or purging raise concern. (4) If you are trained, use evidence-based eating-disorder treatment; otherwise refer.
Example language (illustrative): "What you've described worries me, and I don't think fasting is safe for you right now. Can we look at getting a proper assessment of your eating first?"
Watch for: the client turning to an unsupervised fast instead; keep contact and see 4.8.

4.7 Integrating the experience afterwards

Purpose: help the client make sense of what they felt and keep changes that support well-being without rigid rules.
Steps: (1) Invite an account of the cure: hardest moments, surprises, body experience. (2) Separate useful changes (rhythm, rest, mindful eating) from rules that create anxiety. (3) Plan for rebound eating or urges to fast again. (4) Link insights to the therapy's goals.
Example language (illustrative): "What from those days do you want to keep, and is there anything you've brought back that feels more like a rule than a choice?"
Watch for: new food rules, guilt after normal meals, repeated fasting, binge-restrict cycles. Working well: flexible eating and stable mood.

4.8 Responding to plans for unsupervised or extreme fasting

Purpose: respond safely when a client plans a prolonged water fast, a "detox" retreat without medical staff, a dry fast, or "breatharian" living on "light" or "prana" (these concepts belong to the groups that teach them).
Steps: (1) Ask what the plan is and who is behind it. (2) Say plainly that deaths have been reported in people trying to live without food (Harm account). (3) Explore the need behind the plan. (4) Urge medical assessment and offer to help arrange it. (5) If capacity or an eating disorder is in question, or a third party is pressing the person, follow your service's safeguarding and risk procedures.
Example language (illustrative): "I'm not going to pretend I'm comfortable with this. People have died attempting to live without food. Can we talk about what this would give you, and get a doctor's view first?"
Watch for: group pressure, secrecy, a teacher who discourages medical care. Working well: the client delays the plan and accepts medical input.

4.9 Responding to a physical warning sign

Purpose: act quickly on signs that may indicate electrolyte disturbance, refeeding problems or low blood sugar.
Steps: (1) If a client fasting or recently refeeding reports confusion, fainting, marked weakness, palpitations, breathlessness, swelling or a seizure, advise immediate medical help (clinic staff, GP same day, or emergency services if severe) [warning features drawn from NHS Highland, citing NICE CG32]. (2) Do not reassure or give dietary advice. (3) Record and follow up.
Example language (illustrative): "That needs a doctor now. Can you call the clinic, or shall I call emergency services with you?"
Watch for: the client wanting to "push through" because symptoms are framed as a "healing crisis" or detox; this is the tradition's language, not a medical assessment.

5. Handling problems

The sources describe the medical method, not the psychotherapist's problems. Everything in this section is [synthesis] unless a source is named.

The client wants your blessing or a plan. Give neither a plan nor reassurance. Response: "I can help you think it through and get the right doctor involved, but the fasting itself is a medical decision." Then 4.3.
The client asks about medicines (insulin, other glucose-lowering drugs, blood-pressure tablets, diuretics, lithium, psychiatric medicines). Never advise. Response: "That is a question for your prescriber before you start, and please don't stop or change anything yourself." NICE-based guidance lists insulin and diuretics among medicines that affect electrolyte risk [source: NHS Highland, citing NICE CG32]. The 2013 guideline lists psychotropics (especially neuroleptics and lithium), antidiabetics, antihypertensives (especially beta-blockers and diuretics), anticoagulants, anti-inflammatory painkillers, systemic corticosteroids, anticonvulsants and hormonal contraceptives (reduced effect) among medicines the fasting physician must review [source: Wilhelmi de Toledo et al. 2013, full text]; this is the physician's task, not yours.
Minimising or hiding eating history. Keep the door open and return to it: "Sometimes people don't mention this because they worry they'll be told no. What would be hard about the clinic knowing?" If concern stays high, advise against fasting and see 4.6.
Resistance: "fasting is natural, doctors don't understand it." Do not argue about theory. Agree on safety: "Whatever we each think of the theory, the fasting doctors themselves say it should only be done with a trained physician." [source for the claim about doctors: Wilhelmi de Toledo et al. 2013, abstract].
Non-adherence to the medical plan (fasting longer than advised, skipping the refeeding phase, adding extra laxatives). Treat as a possible restriction or purging signal; explore the function; with consent, inform the physician.
Overwhelm or low mood during the cure. Encourage the client to tell clinic staff the same day; offer a short contact; if mood falls sharply or suicidal thoughts appear, follow standard risk procedures and involve the physician. Stopping the fast is a medical decision taken with the clinic team.
Emotional material surfacing (grief, trauma memories, body shame), including after abdominal treatment (A5). Contain and ground; schedule time to work with it after the cure rather than deep processing while the client is physically depleted.
Rebound eating or guilt after refeeding. Normalise urges without moralising; watch for binge-restrict cycles; offer eating-disorder assessment if the pattern persists.
Repeated or escalating fasts. Ask what each fast is for; if fasting has become a main way of regulating emotion or weight, treat it as a possible eating disorder (4.6).
Rupture: the client feels judged for wanting to fast. Repair directly: "I came across as against this, and I want to understand what it means to you. My job is to make sure it's safe, not to decide for you."
Spiritual or group framing (purification, "living on light"). Attribute the concept to the group, stay curious about its meaning, and keep the safety line clear (4.8). If a group or teacher discourages medical care, consider safeguarding.
Adolescents. Do not support self-chosen fasting for a minor; involve parents or carers and the child's doctor under your safeguarding framework.
A client in recovery from an eating disorder who wants a "supervised" fast. Leading clinics do not treat anorexia or bulimia [source: Buchinger Wilhelmi]; discuss relapse risk openly with the client and their eating-disorder team before anything else.

Harm account

This section covers harms from fasting outside or beyond medical supervision, and the known medical risks of fasting and refeeding in general. It is not a claim that supervised clinic fasting causes these outcomes; an observational study in a specialised clinic reported adverse events in under 1% of participants [source: PLoS ONE 2019, abstract]. A chart review of adverse events during medically supervised water-only fasting (Finnell et al. 2018) appears in the ÄGHE literature list; its findings are not summarised here.

What was actually done

"Breatharian" or inedia teaching. The Australian teacher known as Jasmuheen promoted the idea that people can live without food on "light" or "prana" (the movement's own concepts). In 1999 the Australian programme 60 Minutes filmed her attempting to live without food and water under a doctor's observation; the doctor stopped the test after a few days, reporting acute dehydration, stress, raised blood pressure and a much faster pulse, and warning of kidney failure if it went on [source: Wikipedia, Jasmuheen, citing Yahoo News 25 Oct 1999] [uncertain: Wikipedia only].
Deaths reported in followers. Reported cases include: a woman in Australia who died in 1999 after following a breatharian regimen; two followers who had been with her were later convicted of manslaughter, with reports stating that seeking medical attention had been delayed [source: Wikipedia, citing The Courier-Mail 27 Nov 1999]; a woman found dead in a tent in Scotland (1999), whose diary referred to these teachings and whose death involved hypothermia and dehydration with lack of nutrition [source: Wikipedia, citing The Herald 1999 and BBC 2000]; a Swiss woman (2012) reported to have starved after trying to live on light, as taught in one of Jasmuheen's books [source: Wikipedia, citing Herald Sun 26 Apr 2012]; a Dutch woman (2017) in a household of breatharian practitioners, where the others were suspected of withholding medical care [source: Wikipedia, citing NRC Handelsblad 2017]; and a 22-year-old German man in Dominica (2017) who reportedly stopped eating and drinking, saying he planned to live on sunlight [source: Wikipedia, citing FOCUS Online and NDR 2019]. Jasmuheen has denied responsibility [source: Wikipedia]. Every case in this paragraph rests on Wikipedia's summary of the press reports it cites [uncertain: secondary, unverified].
Unsupervised prolonged fasting and "detox" programmes. Fasts done at home or at retreats without a physician, often combined with laxatives or bowel cleansing and framed as "detox". Reference sources describe detox claims for fasting as disputed and note that fasting raises uric acid and drives loss of muscle as well as fat [source: DocCheck Flexikon, Heilfasten].
Abrupt return to eating after starvation or prolonged fasting, without monitoring, in people at risk of refeeding syndrome [source: NHS Highland, citing NICE CG32].

How it caused harm

Refeeding syndrome. During starvation, body stores of potassium, magnesium and phosphate are depleted even when blood levels look normal; when feeding restarts, insulin moves these into cells, blood levels fall, thiamine is used up quickly, and salt and water are retained. Consequences include heart rhythm disturbance, heart failure, cardiac arrest, respiratory failure, weakness, seizures, confusion, coma, kidney failure and Wernicke-Korsakoff syndrome. It typically appears within the first days of refeeding [source: NHS Highland refeeding guideline, citing NICE CG32 Nutrition support for adults, 2006]. Whether CG32 has a current successor [uncertain: not verified].
Who is most at risk (qualitative, after NICE). People with very low body weight, marked recent unintentional weight loss, little or no intake for many days, low electrolytes before feeding, a history of alcohol misuse, or taking medicines that affect electrolytes (such as insulin, chemotherapy, antacids or diuretics); also people after prolonged fasting, with malabsorption or prolonged vomiting or diarrhoea, with anorexia nervosa, or with severe vomiting in pregnancy [source: NHS Highland, citing NICE CG32].
Electrolyte disturbance and dehydration. Low potassium, magnesium and phosphate cause arrhythmia, muscle weakness and confusion [source: NHS Highland]; going without fluid adds dehydration and the risk of kidney failure, as in the 1999 televised test [source: Wikipedia, Jasmuheen] [uncertain: Wikipedia only].
Hypoglycaemia. Blood glucose falls during fasting, reaching the low-normal range in the 2019 clinic study [source: PLoS ONE 2019, abstract]. People taking insulin or other glucose-lowering medicines are at risk of dangerous low blood sugar if they fast without their prescriber adjusting treatment [synthesis; the 2013 guideline lists antidiabetics among medicines the fasting physician must adjust, Wilhelmi de Toledo et al. 2013].
Medication interactions. Fasting changes the effect and safety of medicines that affect glucose, electrolytes, blood pressure or fluid balance; the clinic provides supplements for guests on strong or complex medication [source: Buchinger Wilhelmi; NHS Highland]. Any adjustment is for the prescriber alone.
Triggering or worsening eating disorders. Leading fasting clinics exclude anorexia and bulimia [source: Buchinger Wilhelmi]. A review article notes studies suggesting that fasting may predict eating pathology more strongly than dietary restraint, while a small preliminary study of short fasting in students did not show a clear increase in binge eating [source: Eating Disorders Review 2012, Anderson and Schaumberg]; the primary studies [uncertain: not verified]. Clinically, fasting can start or re-start restriction, binge-purge cycles, laxative misuse and food rules [synthesis].
Death. The reported breatharian deaths above involved starvation, dehydration and hypothermia, and in at least one case delayed medical care, with criminal convictions [source: Wikipedia, citing press] [uncertain: Wikipedia only].
Psychological sequelae. Guilt, shame and self-blame after "failing" a fast, grief and trauma for relatives of those who died, and group pressure that discourages medical help [synthesis].

Recognising it today

Phrases and claims: "living on light" or "prana", "you don't need food or water", "detox", "cleansing", "flushing toxins", a "healing crisis" as the reason to ignore symptoms, fasting presented as a cure for cancer or serious disease, and promises of rapid weight loss [synthesis; detox framing contested per DocCheck Flexikon].
Programme red flags: no medical intake examination; no physician on call; no screening for eating disorders, pregnancy, diabetes or medicines; prolonged water or dry fasting; routine laxatives or bowel washes without medical oversight; no planned refeeding phase; advice to stop medicines; pressure to continue despite fainting, confusion or palpitations; leaders who discourage contact with doctors or family [synthesis, contrasted with Buchinger Wilhelmi and ÄGHE practice].
Red flags in a colleague's practice: a therapist who prescribes or coaches fasting, sets weight goals, endorses detox theories as fact, or discourages medical care [synthesis].
How legitimate versions differ: a physician or certified fasting therapist guides the whole intervention [source: Wilhelmi de Toledo et al. 2013, abstract]; there is a medical examination at the start, adjustment for medication and frailty, exclusion of people with eating disorders and dependencies, a planned refeeding phase and after-care [source: Buchinger Wilhelmi]; providers are listed by the ÄGHE or hold a recognised F. X. Mayr qualification [source: ÄGHE page; Witasek 2019].

What to do instead and how to help those harmed

Safer alternatives: for health aims, the client's GP or specialist; for a structured fast, only a qualified fasting physician or clinic after medical assessment; for those excluded from fasting, the clinic's non-fasting nutritional programmes [source: Buchinger Wilhelmi]; for spiritual or meaning-seeking aims, non-fasting contemplative practice [synthesis].
Urgent physical risk: a person who has been fasting or starving and is confused, faint, very weak, breathless, has palpitations or a seizure, or is restarting food after prolonged restriction, needs immediate medical care; refeeding of at-risk people belongs in a monitored medical setting [source: NHS Highland, citing NICE CG32; synthesis].
Assessment of affected clients: eating-disorder screening and referral to specialist services; mood, trauma and suicide-risk assessment by standard practice; ask about group membership and coercion; liaise with the GP for physical monitoring [synthesis].
Treatment considerations: evidence-based eating-disorder treatment where indicated; trauma-informed work for coercive group experience; grief work for bereaved relatives; avoid shaming the client for having believed the claims [synthesis].
Ethical, reporting and legal duties: act on imminent risk to life under your service's emergency and safeguarding procedures; consider capacity where starvation impairs judgement; safeguard children and vulnerable adults in households or groups that withhold food or care; report concerns about practitioners to the relevant regulator or professional body; document decisions [synthesis; duties vary by jurisdiction].

Sources

Web pages:

Publications cited:

Wilhelmi de Toledo F, Buchinger A, Burggrabe H, Hölz G, Kuhn C, Lischka E, Lischka N, Lützner H, May W, Ritzmann-Widderich M, Stange R, Wessel A, Boschmann M, Peper E, Michalsen A (2013). Fasting therapy – an expert panel update of the 2002 consensus guidelines. Forschende Komplementärmedizin 20(6): 434–443. DOI 10.1159/000357602 (open access).
ÄGHE (2002). Leitlinien zur Fastentherapie, 1. Fassung. Forsch Komplementmed 9: 189–198 (as listed by the ÄGHE) [uncertain: listing only].
Witasek A (ed.) (2019). Lehrbuch der F.X. Mayr-Medizin: Grundlagen, Diagnostik und Therapie. Berlin/Heidelberg: Springer (publisher description only).
NICE (2006, last reviewed 2017). Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition (CG32). The NICE page, in a 2026 UK Government Web Archive capture, gives the 2017 review as the latest change, says the guideline will be reviewed if new evidence is likely to change the recommendations, and names no successor guideline.
Anderson D, Schaumberg K (2012), as reported in Eating Disorders Review 23(5).
Finnell et al. (2018). Is fasting safe? A chart review of adverse events during medically supervised, water-only fasting (as listed by the ÄGHE).

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