Chewing and Spitting: A Neglected Symptom in Eating Disorders?

Eating disorders come in all shapes and sizes, but all of them are characterized by the same goal: to avoid weight gain or induce weight loss. While behaviours such as food restriction, purging, and laxative abuse are relatively well studied, chewing and spitting (CHSP) is not. A simple Google search, however, reveals over 1.5 million results for the term “chewing and spitting.” Results often links to blog posts or Tumblr pages where CHSP sufferers confess their guilt, disgust and obsession with the behaviour.

What is chewing and spitting? How does it relate to other disordered eating behaviours  such as restrictive eating or binge eating?

Chewing and spitting describes the pathological eating behaviour where the individual chews a variety of enjoyable foods, and spits it out to avoid undesirable consequences of weight gain (Mitchell et al, 1988). This seemingly “smart” workaround allows them to enjoy the taste of foods they usually deny themselves. However, CHSP is described as “driven and compelling,” often leading to uncontrollable episodes in which the individual chews and spits out large quantities of food. This type of behaviour often results in social isolation, severe food obsession and financial difficulties.

Given the phenomenological similarities between CHSP and binge eating, CHSP was previously mostly examined in the context of bulimia nervosa (BN). While chew and spit is fairly common in patients with BN (64.5% of 275 patients with BN over the course of their lifetime), few patients engaged in the behaviour continuously (Mitchell et al., 1985). In fact, chewing and spitting was considered an intermittent purging behaviour used in place of self-induced vomiting or laxative abuse. A more recent survey of individual with anorexia nervosa (AN), BN and eating disorder not otherwise specified (EDNOS) revealed that chewing and spitting was not limited to patients with BN (Kovacs et al., 2002). Patients who reported engaging in this type of behaviour in the AN and EDNOS group demonstrated more disturbed eating behaviour than their non-chewing and spitting counterparts.

In this study, Guarda and colleagues set out to evaluate the prevalence and frequency of chew and spit in patients with AN, BN and EDNOS, and compare depression and disordered eating behaviours between individuals who chew and spit to those who do not. Self-report questionnaires included the Beck Depression Inventory (BDI), which measures depressive symptomatology, and the Eating Disorder Inventory-2 (EDI-2) questionnaire, which measures eating disorder symptomatology. Overall, 301 patients were surveyed.

So what did they find?


  • Prevalence: 34% admitted to one episode of CHSP in the month prior to admission, with 19% engaging in the behaviour several times a week (CHSP+).
  • Compared to patients who did not CHSP or did so once a week or less (CHSP-) CHSP+ patients were younger, significantly more likely to abuse diet pills, engage in excessive exercise, skipping meals and restrict fat and calories. The authors further examined if this difference in disordered eating occurred in all groups (AN, BN and EDNOS), and found that it was seen only in the AN group. In other words, AN patients who engaged in CHSP reported more of the above behaviours than AN patients who did not. On the other hand, CHSP did not significantly alter eating behaviours in BN and EDNOS groups.
  • Overall BDI scores were not different between CHSP- and CHSP+ patients, although CHSP+ patients were more likely to have considered suicide.
  • There were no significant differences in mean length of stay as an inpatient, race or current employment between CHSP groups.
  • There were no significant differences in BDI or EDI-2 in CHSP+/- patients who also engaged in binge eating.

Making sense of these results

Contrary to previous belief, chewing and spiting was not limited to BN patients, but appeared to be equally prevalent among eating disorder subtypes. However, AN patients who engaged in CHSP tended to be more pathological in their disorder than AN patients who did not. CHSP did not influence eating behaviours of patients with BN or EDNOS. Surprisingly, CHSP was more commonly associated with other restricting eating behaviours than binging and purging.

However, as the authors noted, a limitation of this study was that they did not assess the amount of food consumed during each chew/spit episode or associated loss of control. Patients generally choose sugary or high fat food to chew and spit, hinting at a reward system deregulation that is also found in patients with binge eating disorder. Future studies should address the macronutrient composition and amount of food consumed in a sitting as well as the individual’s state of mind to characterize this frequent eating disordered behaviour and its reinforces.


Guarda, A., Coughlin, J., Cummings, M., Marinilli, A., Haug, N., Boucher, M., & Heinberg, L. (2004). Chewing and spitting in eating disorders and its relationship to binge eating Eating Behaviors, 5 (3), 231-239 DOI: 10.1016/j.eatbeh.2004.01.001


Shelly is a PhD Candidate in Neuroscience at the University of British Columbia. Her work focuses on protein degradation in neurodegenerative diseases, and she has minor projects in epigenetics and the cellular mechanisms behind learning and memory. Shelly has struggled with restricting-type anorexia nervosa, with chewing and spitting as a major symptom.


  1. I’m glad this is finally being addressed. I know it was a symptom I suffered from as did many others I know. Even in the various treatment types/places I’ve had chewing and spitting was barely if at all discussed. It’s something that contributed to a HUGE part of the shame I felt in my disorder, so I hope that by it becoming more readily addressed, it can take away some of the shame it holds for those trying to seek treatment. Thanks for sharing this info!

    • My pleasure! I’m really glad there’s interest in this topic – I’ve seen it discussed on forums and blogs but never formally. Hopefully we can all learn together 🙂

  2. Thank you (and hello Shelly 🙂 )
    I’m glad this is being written about, there isn’t much out there about this.
    I’ve read in places suggestions that there are actually quite grave medical consequences to chewing and spitting – I can’t quite remember what they were but I think it was because the act of having the food in our mouths, chewing it etc, means our body prepares to consume it, along with a release of the associated digestive chemicals/juices – and then doesn’t get that food. I’ve heard diabetes as one possible complication… what do you think? Thank you.

    • Hi Fiona! Good to hear from you!
      Yes I have heard about those medical issues you mentioned above. What they’re talking about is called the “cephalic response”, where the sight, smell and taste of food induces a release of insulin and other hormones associated with hunger regulation. It’s thought that this may deregulate the satiety system and metabolism, eventually leading to metabolic syndromes such as diabetes. HOWEVER most of the research is done in animal models – I’m not entirely sure this occurs in humans at a level that is physiologically-relevant.
      This is definitely something I’ll look deeper into and blog about 🙂

      • It’s really interesting – and it’s terrifying that something so seemingly ‘harmless’ could well have devastating consequences.

  3. This is fascinating – I am new to this topic, but interested in learning more about reward system deregulation as it relates to eating or binge eating. Do you suggest any papers or books that would give an overview or background on that?

    • Hi Michelle!

      Off the top of my head,

      Marazzi M et al (1997). Endogenous codeine and morphine in anorexia and bulimia nervosa. Life Sciences, 60, 1741-1747.

      Kelley AE et al (2000). A pharmacological analysis of the substrates underlying conditioned feeding induced by repeated opiod stimulation of the nucleus accumbens. Neuropsychopharmacology, 23, 455-467.

      Both are about the potential role of the opiod reward system. It’s an extremely interesting (and important) topic, and definitely one I’d like to look into further 🙂

      Tetyana’s better read in the field, and might have more suggestions.

  4. Thank you SO MUCH for writing about this. Like others have mentioned, this behavior is not talked about a lot and that adds to the shame. I developed this behavior over a year ago and it has been utterly devastating to overcome and is still a daily battle. I think the worst part is the shameful feelings that come with it.

    I work in ED research and I’m applying to grad school now, I would eventually love to study this behavior. There is not much literature on it and that needs to change!

    Anyhow, thanks so much for bringing this to light. It makes me feel a lot less alone.

    • I didn’t write the post–but I’m very happy to hear that it has made you feel a lot less alone. I agree: we need more research.

    • I’m REALLY happy this post helps 🙂 I hope all goes well with your research -it’s a bit shameful how science can lack behind sometimes.

    • Kmari1222:
      Thank you SO MUCH for writing about this. Like others have mentioned, this behavior is not talked about a lot and that adds to the shame. I developed this behavior over a year ago and it has been utterly devastating to overcome and is still a daily battle. I think the worst part is the shameful feelings that come with it.

      I work in ED research and I’m applying to grad school now, I would eventually love to study this behavior. There is not much literature on it and that needs to change!

      Anyhow, thanks so much for bringing this to light. It makes me feel a lot less alone.

      Hey, thanx for your honesty. I can relate to your daily battle! I am going bat shit crazy trying to end this, I am dreading all the summer engagements round the corner! I found this on google and I am trying the program out, I need help!

      • I’m glad you replied, I have been feeling really bummed lately about this. I checked out that program, it actually looks pretty neat! Would you mind if I asked you a couple questions about it? I’d love to chat with you about the ups and downs of recovery!!!

  5. You write: “Eating disorders come in all shapes and sizes, but all of them are characterized by the same goal: to avoid weight gain or induce weight loss.”

    How does that apply in the case of binge eating with weight gain?

    • Hi Beth,

      I can’t answer for Shelly (the author of this post) but I actually don’t think that avoiding weight gain or inducing weight loss is necessarily the goal of any eating disorder (anorexia nervosa, bulimia nervosa, or binge eating disorder), and often enough, in cases of AN and BN, it isn’t really the goal (particularly when it progresses to the stage of an eating disorder, as opposed to disordered eating).

      Having said that, while I don’t know enough about BED, but I do suspect for many, it might develop into a cycle of trying to lose weight/restrict/skip meals and then, having failed to maintain that for a prolonged amount of time, bingeing. I’m sure that’s not the case for everyone, but I do suspect that it may start out being about trying to lose weight or maintain weight loss, failing and bingeing, which would lead to another episode of restricting (to counteract the binge), and so on.

      Personally, I think eating disorders are about using food or food-related behaviours to regulate affect.

  6. I have BN. Unfortunately the CHSP I do is not recognized by my rehabilitation facility as ED behavior and is not being addressed. My BN is getting better, I’m no longer binging and restricting for days/weeks after, but I still CHSP daily. I hope that this will soon be recognized by my program so that I can freely bring it up and deal with it during my therapeutic sessions. Thank you for your research.

    • Hi June, I’m really sorry to hear that! Would it be possible to point your program to the papers that describe CHSP? On the bright side, CHSP was mentioned by Mary Roach, an extremely popular science write, in her new book “Gulp”. I think it is increasingly getting noticed, by both media and (hopefully) the medical community.
      Hang in there and congrats on your progress!

  7. Iam so relieved to see this shameful and embarrassing disease being brought to the surface, I have suffered with this chsp for over 5 years…daily struggle but I can only hope that one day all of you struggling with any part of ED find balance and joy in the life you were meant to live.
    Looking forward to more posts of chewing and spitting.

    • Hi Amber, thank you so much for your comment! My main goal for blogging about CHSP is to start a conversation without shame or any negativity – to try to understand what might be going on in our heads and bodies. I feel talking about it helps 🙂
      If you have any suggestions on topics relating to CHSP please let me know! Unfortunately there’s not a whole lot of research out there, but regardless we might still be able to find some answers.

  8. Hi Shelly-

    Thanks so much for your very interesting post – this is certainly a disorder that few people know lots about – yet many people suffer from it.


  9. My mother engages in CHSP all the time. The amount of food she actually swallows is probably fit for a rabbit. I’m really worried if she has an extreme eating disorder, but when I approached her on it one day she got really angry. She’s had many severe food obsessions in the past and sometimes $100 worth of food disappear from the kitchen overnight. Everyday she’ll eat a huge handful of pills for faster digestion and better skin/nails. She also exercises a lot; two years ago she bought this workout outfit that “made you sweat more”–at least that’s what the label said. She always spends an excessive amount of money buying food when our family really doesn’t have the money for that anymore, and the worst part is she never really eats it–it all just goes to waste. Is there anyway I can help my mom?

  10. My nutritionist showed me this blog, and it was really helpful to read. I’ve been in recovery for AN for 2 months, and have recently developed into chewing and spitting. It feels so shameful and disgusting and I feel horrible about doing it, but it’s like I really can’t help it. I’m just glad to know I’m not the only one struggling with this…thank you

  11. I’ve written a short kindle book on how to beat Chew and Spit. It’s ways I have used to recover so I’m 90% free now. This site helped me understand what it was doing to my body and I’ve included the link 🙂

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