- Evidence suggests that vegetarianism and veganism can both precede and follow on from the start of an eating disorder.
- Regardless of initial cause and effect, reversal of the V/V habit may be the only way to disrupt the mutually supportive feedback dynamics.
- If you cut out one type of food, you get some “benefits” from it, and it becomes more likely that you cut out another.
In Part 1 of this series we took a look at the ethics trick as one easy way that vegetarianism and veganism (henceforth V/V) get themselves installed. The appeal of an all-or-nothing cognitive shortcut applies to everyone making dietary decisions in a complex world, but the trick’s illusion of simplicity is more dangerously deceptive in the eating-disorder context. In this part of the series we’ll survey the evidence and potential reasons for both correlations and causal relationships (one way or the other) between V/V and EDs.
It’s clear that vegetarianism and veganism (henceforth V/V) are far more common amongst people with eating disorders than in the general population. A recent meta-analysis (Sergentanis et al., 2021) found significant correlations between vegetarianism and eating disorders in adolescents and young adults, particularly in anorexia and particularly amongst females. And particularly for adolescents, correlations were found between vegetarianism and unhealthy and extreme weight-control behaviours. An earlier study (Bardone-Cone et al., 2012) found that 33% of participants with a current eating disorder were currently also vegetarian, as opposed to 13% of partially recovered people and 5% of fully recovered people.
Anecdotally, amongst my blog readers and coaching clients, “long-term vegetarian/vegan with eating disorder” is a very common descriptor. Of course, some people with anorexia do keep meat (usually “lean”) in their diet—these are often the people who eliminate most carbs instead—but cutting out meat is a remarkably common first step in the eliminative process that ends in anorexia. And if it predated the eating disorder proper, as it often does, it feels less totally pathological than the calorie-counting or the non-meat fear foods. So it’s often something that survives unchallenged into the recovery phase.
In this series I’m arguing that refusing to eat meat is also one of the major factors that make successful recovery so rare. My basic claim is that the ethics trick really is no better than a trick if it folds genuine ethics into a survival package for your eating disorder.
So, if you currently have a restrictive eating disorder and aren’t eating meat (and maybe no other animal products either), I invite you to read what follows with as open a mind as you can muster, and keep a little question uppermost for yourself throughout: “What might change if I tried it?”.
What causes what? Feedback
So, OK, we know that eating disorders and V/V go hand in hand. But that doesn’t necessarily tell us which is causing the other, if either (both may instead be caused by something else). There’s certainly a good deal of anecdotal evidence for causal links in both directions.
Eating disorders causing V/V is a pretty obvious pathway: The eating disorder is about restricting eating, and eliminating food groups is a simple way to do this. Therefore V/V is great at adding another notch to a longer and longer “I won’t eat this” list. It also has the benefit of a convenient social legitimacy: Tabitha Farrar observes that “being vegan allowed me to showcase my eating disorder in public”, and Hal Herzog quotes an interviewee remarking that "for some women, giving up meat is not so much a matter of ethics but a politically acceptable form of extreme weight control". In support of this direction of causality, the 2012 study I cited above found that most participants who had a history of an eating disorder and of vegetarianism reported that the eating disorder preceded the adoption of a vegetarian diet. None of the healthy controls but half of the eating disorder sample reported that their V/V had been motivated by primarily weight-related reasons.
There's less direct evidence for it, but V/V causing restrictive eating disorders is very plausible too: You cut out one thing, you get some “benefits” from it, and it becomes more likely that you cut out another. You impose energy deficit, and if your genetic and environmental conditions are set up for it, energy deficit easily becomes a self-perpetuating habit, with multiple cognitive knock-on effects. As one reader commented some years ago, “I don't believe my desire to become vegetarian and my descent into anorexia is linked but maybe there is something to be said for initiating a habit of restriction, and creating an environment where anorexia could take hold” (Diana, on the post "Biscuits before breakfast: Recovery in microcosm", 28 May 2018 [all comments were sadly deleted from the PT site in spring 2021]). This is echoed by a remark in the 2021 meta-analysis:
In a patient with an eating disorder and vegetarianism, there is a high likelihood that vegetarianism could represent a mode of restriction in eating habits, as a part of their eating disorder pathology. Perpetuation of pathology cannot be ruled out, in a vicious circle where restriction begets restriction. (Sergentanis et al., 2021)
Similarly, Bardone-Cone and colleagues remark that “vegetarianism may provide the individual with additional 'good food'/'bad food' dichotomies that would simplify her/his life”. These effects play out at the level of life priorities and big-picture decision-making, but it's all tied to the basic biochemistry. A vegetarian and especially a vegan diet is likely to result in deficiencies in minerals like iron, zinc, calcium, iodine, vitamins like B12 and D3, antioxidants like carnosine, fatty acids such as DHA, and other compounds like creatine and taurine (see e.g. Bakaloudi et al., 2021; plus overviews here and here). All of these are possible to obtain by supplementation, but not all sources have equal effects. By helping drive even minor cumulative effects of micronutrient inadequacies on brain function and physical performance, V/V may contribute to getting anorexia installed and then keeping its physiological and cognitive-emotional dysfunctions entrenched.
Whether or not there was an obvious causal chain right at the start, both the previous two quotes intimate that feedback processes can easily kick in to make it fairly irrelevant what the “starting point” really was. (There is never a starting-from-nothing point.) Spinning origin stories is very little use at all if the end goal is recovery rather than storytelling (Troscianko and Leon, 2020). Once feedback is involved, its dynamics are what matter, and solutions not starting points are what count.
Let’s look at a simple example in the physiological context. The less meat and dairy you eat (in terms of both quantity and variety), the less your digestive system can tolerate, because production of specific protein-directed enzymes reduces over time. This means if you do make an exception and have a steak or a milkshake or whatever, you might experience some digestive upset, which will make you more inclined to keep avoiding what you’re already avoiding, and to eliminate more things in a backwards quest for digestive comfort. As ever, the feedback loop is simple to break into, and doing so can work wonders, often quite quickly: If you find you’re growing “intolerant” to more and more things, reintroducing a food type as valuable as meat is an efficient way to get missing nutrients, help rebuild your digestive system (and the rest of your body), and stop the psychology of restriction in its tracks too. If you take it slowly there’s no reason to expect your body not to readjust within weeks. Your genetic potential to produce the relevant enzymes won’t have changed.
Of course, all the same arguments apply to the broad-based wreckage done to a digestive system by chronic malnutrition: From stomach shrinkage to reduced transit times, there is nothing comfortable about the malnourished digestive process, but there’s usually nothing to prevent it all getting back to normal with refeeding. That just requires acute transition phase to be got through, and switch the vicious positive feedback (experience digestive discomfort, eat less to mitigate it, make your digestive system less able to cope with everything, experience more digestive discomfort) into a dynamic that generates stability (experience digestive discomfort, eat more despite it, make your digestive system more able to cope with everything).
Thanks to the ease with which the causal chains linking V/V and eating disorders can be established, in either direction, and the ease with which, once established, self-perpetuating feedback cycles between the two are generated, there’s a strong case for breaking the connection from the V/V end if recovery is your aim. As I say, once you have feedback dynamics in play, it doesn’t matter where they started: Your ethical qualms may absolutely have been uppermost, but that is now irrelevant if your question is what is helping sustain my eating disorder and how can I make it stop doing so.
In the next part of the series we’ll go into a bit more detail on the question of costs and benefits, and specifically the question of whom they accrue to.
Bakaloudi, D. R., Halloran, A., Rippin, H. L., Oikonomidou, A. C., Dardavesis, T. I., Williams, J., ... & Chourdakis, M. (2020). Intake and adequacy of the vegan diet. A systematic review of the evidence. Clinical Nutrition, 40(5), 3503-3521. Direct PDF download here.
Bardone-Cone, A. M., Fitzsimmons-Craft, E. E., Harney, M. B., Maldonado, C. R., Lawson, M. A., Smith, R., & Robinson, D. P. (2012). The inter-relationships between vegetarianism and eating disorders among females. Journal of the Academy of Nutrition and Dietetics, 112(8), 1247-1252. Open-access full text here.
Sergentanis, T. N., Chelmi, M. E., Liampas, A., Yfanti, C. M., Panagouli, E., Vlachopapadopoulou, E., ... & Tsitsika, A. (2021). Vegetarian Diets and Eating Disorders in Adolescents and Young Adults: A Systematic Review. Children, 8(1), 12. Open-access full text here.
Troscianko, E. T., & Leon, M. (2020). Treating eating: A dynamical systems model of eating disorders. Frontiers in Psychology, 11. Open-access full text here.