Ketamine and Eating Disorders: Is There a Connection?

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What the research tells us about appetite, weight loss and restrictive eating — and why practitioners may need to explore questions that research cannot yet answer.

During recent KASPR practitioner training in Kent, an interesting question emerged from a discussion with an experienced CBT therapist. She had encountered women who began using ketamine before subsequently developing eating disorders.

Could the two be connected? Might some people find that ketamine makes restricting food intake easier? And, if so, could this become another reason for continuing to use it?

These are important questions, particularly because the relationship between substance use and eating disorders is not new. However, the specific relationship between ketamine and restrictive eating remains poorly understood.

There is some emerging research, but the evidence is not yet sufficient to establish whether ketamine contributes directly to the development of eating disorders.

A familiar relationship: drugs and weight control

The use of substances to manage appetite and body weight has a long history.

Amphetamines, sometimes known as speed, were widely prescribed as appetite suppressants during the twentieth century. Their ability to reduce hunger and food intake became recognised during the 1930s, although concerns about dependence and other harms eventually restricted their use (Rasmussen, 2015).

Beyond their physical effects, substances may acquire psychological functions. Someone may value the experience of reduced hunger, greater control over eating or temporary relief from distress associated with food and body image.

However, ketamine is not an amphetamine. It is a dissociative anaesthetic with different effects on the brain and body.

We therefore cannot assume that ketamine suppresses appetite in the same way as stimulants. Nevertheless, there are several reasons to consider whether ketamine use might become associated with changes in eating behaviour.

What do we know about ketamine and appetite?

Appetite disturbance has been reported among people experiencing problems with ketamine use. In a survey involving 274 people who identified as having ketamine use disorder, Harding et al. (2025) found that 24% reported poor appetite during periods of abstinence or withdrawal.

This suggests that appetite difficulties may accompany changes in ketamine use, although it does not establish whether ketamine directly suppresses hunger or leads to a sustained eating disorder.

There may also be indirect explanations.

Frequent ketamine use can be associated with abdominal pain, nausea and vomiting. These experiences may make eating uncomfortable or reduce someone's desire to eat.

Daily routines may also become disrupted. Someone using ketamine frequently might miss meals, neglect food preparation or find that eating becomes less important than obtaining and using the drug.

The Advisory Council on the Misuse of Drugs (2026) identifies poor appetite among reported ketamine withdrawal symptoms, while also recognising the limitations of the available evidence.

Importantly, reduced appetite, inadequate nutrition and anorexia nervosa are not interchangeable terms.

A person may lose considerable weight because of pain, nausea or irregular eating without developing an eating disorder. Conversely, someone may experience significant eating-disorder symptoms without being visibly underweight.

An emerging finding: Ketamine and leptin

One interesting development concerns leptin, a hormone involved in regulating appetite and communicating information about the body's energy stores to the brain.

Huang et al. (2024) examined leptin levels in 68 people with ketamine use disorder and 62 people without the disorder.

The researchers found lower leptin levels among female participants with ketamine use disorder compared with female controls. The difference remained detectable after two weeks of abstinence.

The same baseline difference was not found among male participants.

These findings are interesting, particularly in the context of questions about appetite and eating behaviour among women using ketamine.

However, they need careful interpretation.

Leptin levels are strongly influenced by body fat and nutritional status. Lower leptin does not necessarily mean reduced appetite; indeed, low leptin normally signals reduced energy stores and can encourage hunger.

Consequently, the findings do not demonstrate that ketamine causes appetite suppression, restrictive eating or anorexia nervosa. They suggest that further research into ketamine, metabolism and hormonal regulation may be worthwhile.

Could ketamine become associated with restrictive eating?

This is where the distinction between research evidence and individual experience becomes particularly important.

Imagine someone who begins using ketamine for its dissociative or recreational effects.

Over time, they notice that they are eating less or losing weight.

Initially, this may be an unintended consequence of ketamine use, gastrointestinal discomfort or disrupted routines.

But what happens if the person welcomes the weight loss?

Could a change that was initially incidental become something they actively value? Might the belief that ketamine makes eating less necessary or less emotionally difficult become an additional reason for continued use?

These are plausible psychological possibilities, but they remain hypotheses rather than established findings about ketamine.

The relationship could also develop differently. Someone might already be experiencing concerns about food, body image or control before those difficulties become more apparent. Ketamine use and restrictive eating might share underlying emotional processes without one directly causing the other.

It is also possible that the two conditions develop independently.

The important question is not simply whether ketamine use and an eating disorder occur together, but whether they influence one another — and, if so, how.

An interesting contrast: Ketamine as a possible eating-disorder treatment

Adding another layer of complexity, researchers are also investigating whether medically administered ketamine might have a role in treating existing eating disorders.

Escobedo-Aedo et al. (2025) reported a small case series involving eight female patients with anorexia-spectrum eating disorders who received ketamine alongside their usual clinical care.

The researchers described improvements in weight and some difficulties involving rigid thinking, food-related anxiety and distress. However, the study involved only eight patients, lacked a comparison group and included several treatments delivered together. It therefore cannot establish that ketamine itself produced the improvements.

These findings are preliminary and do not make ketamine an established treatment for anorexia nervosa.

They also concern carefully supervised medical treatment, rather than repeated non-medical use. Nevertheless, they illustrate how much remains to be understood about ketamine's relationship with eating behaviour.

What can practitioners explore with clients?

When research cannot yet provide a clear explanation, collaborative enquiry can help practitioners and clients better understand the individual's experience.

The aim is not to assume that ketamine has caused an eating disorder, or to impose an explanation on the person.

Instead, practitioners can explore how ketamine use, appetite, eating behaviour and the meaning attached to food or weight may have changed over time.

Some useful areas of enquiry include:

1. Understanding the sequence

When did ketamine use begin, and when did eating patterns start to change?
What did you first notice about your appetite, eating or weight?
What else was happening in your life around that time?

2. Exploring the experience of eating

Does ketamine seem to change how hungry you feel?
Have you noticed differences in your eating when using ketamine compared with periods when you are not using?
Are there times when eating feels physically uncomfortable or emotionally difficult?

3. Understanding the meaning of weight changes

How did you feel about the changes in your weight or eating?
Were those changes worrying, welcome, unwanted or a mixture of different feelings?
Has the importance of food, weight or body shape changed for you over time?

4. Exploring possible connections with continued use

Do you think ketamine has any influence on how you manage eating?
Are there ways ketamine seems to help with difficult feelings about food or your body?
If your ketamine use changed, are there any concerns you would have about what might happen to your eating or weight?

These questions are starting points, not a diagnostic questionnaire. They should be adapted to the person and asked sensitively, without suggesting that a connection must exist.

A practitioner and client may discover that ketamine use and eating difficulties are closely related. Equally, they may discover that the relationship is weak, uncertain or absent. Either finding can be useful.

Where restrictive eating, significant weight loss or suspected eating-disorder symptoms are present, collaborative enquiry should take place alongside appropriate physical health assessment and specialist eating-disorder support. NICE (2017, updated) recommends early assessment and referral for suspected eating disorders, including when substance use is also present.

Understanding the relationship, not just the diagnosis

The relationship between ketamine and eating disorders remains an emerging area of enquiry.

Research provides some evidence of appetite disturbance and possible differences in hormonal regulation. It does not currently establish that ketamine causes anorexia nervosa, or that deliberate food restriction is a common motivation for ketamine use.

Nevertheless, observations emerging from practice raise worthwhile questions.

The KASPR approach emphasises understanding the individual's experience of ketamine use, including the circumstances surrounding use, the difficulties they experience and the functions that continued use may serve.

This can be particularly valuable when other psychological or physical difficulties develop alongside ketamine use.

Two problems occurring together do not necessarily mean that one caused the other. But understanding whether, and how, they interact may be essential to helping someone address both.

Sometimes the most useful contribution a practitioner can make is not to provide an immediate explanation, but to help the person develop a clearer understanding of their own experience.

References

Advisory Council on the Misuse of Drugs (ACMD) (2026) Ketamine: an updated review of use and harms. London: Home Office. Available at: https://www.gov.uk/government/publications/ketamine-an-updated-review-of-use-and-harms

Escobedo-Aedo, P.J., Serrand, C., Kabani, S. and Estric, C. (2025) ‘Ketamine as adjuvant treatment in eating disorders: an exploratory study of a case series and retrospective analysis’, Journal of Eating Disorders, 13, article 48. https://doi.org/10.1186/s40337-025-01232-y

Harding, R.E., Barton, T., Niepceron, M., Harris, E., Bennett, E., Gent, E., Fraser, F. and Morgan, C.J.A. (2025) ‘The landscape of ketamine use disorder: Patient experiences and perspectives on current treatment options’, Addiction, 120(10), pp. 1970–1979. https://doi.org/10.1111/add.70073

Huang, M.-C., Chiang, L.-J., Chien, W.-H., Liu, T.-H., Chen, C.-H. and Liu, Y.-L. (2024) ‘Plasma leptin levels are lower in females, but not males, with ketamine use disorder’, The American Journal of Drug and Alcohol Abuse, 50(5), pp. 659–669. https://doi.org/10.1080/00952990.2024.2394963

National Institute for Health and Care Excellence (NICE) (2017, updated) Eating disorders: recognition and treatment. NICE guideline NG69. Available at: https://www.nice.org.uk/guidance/ng69

Rasmussen, N. (2015) ‘Amphetamine-type stimulants: the early history of their medical and non-medical uses’, International Review of Neurobiology, 120, pp. 9–25. https://doi.org/10.1016/bs.irn.2015.02.001