What determines whether or not anorexia nervosa turns into binge-eating disorder (involving recurrent binge eating in the absence of extreme weight-control behaviours) or bulimia nervosa (recurrent binge eating with extreme weight-control behaviour such as dietary restriction, self-induced vomiting, or laxative misuse)? In the majority of cases of anorexia, extreme and inflexible restriction of dietary intake leads at some point to the development of binge eating, weight regain, and (in about half the cases) bulimia nervosa, or a mixed form of eating disorder 'not otherwise specified' (see Fairburn, 2008: 17). Only a very small number of sufferers remain anorexic throughout - so few that some researchers prefer to see the three 'disorders' instead as a single diagnostic category (e.g. Fairburn, 2008: 18). For clarity's sake, I shall continue here to refer to them as separate conditions, but it is worth bearing in mind the extent to which they are interconnected. The logic of this common progression from restrictive anorexia to binge eating or bulimia is clear: the sustained imposition of restrictions on one's natural appetite leads to ever greater hunger and psychological instability in the form of fixation on food, and at some point one is likely to respond to this, and eat - in a way that feels uncontrollable.
The hunger that years of anorexia creates isn't just the hunger of an empty stomach, although this is part of it; it's the profound malnutrition that means every system and organ in the body is lacking in nutrients - both calories and micronutrients such as vitamins and minerals. Evolutionarily, generalised hunger serves to motivate the organism's search for food in famine conditions, whilst hormonal changes create certain specific dietary preferences: a decrease in leptin production during starvation, for instance, disinhibits nerve signals indicating sweet tastes, making sweet (high-energy) food more attractive. Such changes make it very hard to maintain anorexic behaviour indefinitely - and the longer it continues, the harder it becomes. Trying to maintain it should therefore not be a proud aim for the anorexic. Only self-delusion allows the anorexic to believe that there aren't ultimately just three possible outcomes: death, recovery, or a different eating disorder.
How, then, can the anorexic recover before he or she becomes bulimic - or dies? In my case, there were several factors that, with hindsight, seem to have made it possible for me to avoid both those outcomes, and several related factors that made full recovery possible instead. In discussing those anorexic habits that may have warded against the transition to other eating disorders, I am not suggesting that there are better and worse ways to be anorexic, rather that factors like stability and relatively high calorific intake can make certain outcomes less likely. This does not mean that anorexia in any form isn't comprehensively destructive and potentially fatal.
Firstly, I ate just about enough to keep the hunger always just about bearable, and the physical degradation very slow. When I reviewed the final iteration of my anorexic diet, and added up the total daily calories, which I'd never done when ill, I realised that its three alternating versions were all in fact reasonably calorific: version One totalled 1,655 calories, version Two 1,813, and version Three 1,651. This is more than most strict dieters would consume in a day, and worlds away from the stereotypical anorexic regime of black coffee and half a microscopically chopped apple a day. The difference between this and dieting is that there were no 'cheat days', no lapses, because the primary aim was not weight/fat loss; the hunger and illusion of control became ends in themselves.
In the early years of my decade of illness, there was much greater variation: in the six months leading up to my school exams aged 16, and the month of European travel by myself that followed them, I became practised at missing meals, at telling myself that life would be better if I were slimmer, at learning to love being hungry. Thus I lost 11 kilos in 6 months, and in a year almost 20. Then, with therapy and parentally enforced eating, I put the second 10 kilos back on in another six months, and hovered up and down around the 50kg mark for the next couple of years. Then, in terms of my eating, things stabilised, as I went to university, had the 'freedom' not to eat except what and when I wanted to, and realised that I loved food just as much as I 'needed' the extreme hunger that preceded it. Thus my diet began to set into the pattern it would retain throughout my early and mid-twenties - and the very gentle weight loss of that latter phase set in too. My lowest weight, ten years on from first becoming anorexic, was only 5 kilos less than it was after that first long hot adventurous teenage summer - but there seemed to be a physiological boundary for me around 40 kg (BMI 14.5), which, once crossed, led into the territory of serious emaciation and mental debilitation.
Thus, although the early years of my illness were somewhat nutritionally turbulent, and would therefore have made a good springboard to the greater instability of binge eating or bulimia, somehow that never happened. Perhaps through all the battles with my parents about not-eating, through all the sensations of nausea and entrapment that I experienced when food felt forced upon me, I then still preserved the understanding which returned to me during my final recovery, with relative swiftness: that I love food and don't fear it, and that, crucially, it is only food. And once that phase was over, the stability of intake and relative abundance of food were probably what allowed anorexia to remain in place for so long. This isn't to say that I was not really starving myself: it's important to understand that over seven or eight years of eating around 1,700 calories a day (and with, in my case, an interlude of a few months' concerted if temporary weight gain) it's possible to lose 12 kilos of oneself - one's fat reserves, but also one's bone marrow, muscle, organ tissues - and lose all interest in anything but food.
If one is trying, as I was, to be a 'successful' anorexic, starvation rations in the obvious sense of the term therefore aren't the best way of doing things. The more extreme the starvation, the less sustainable it is. Of course, the concept of 'sustainable starvation' is essentially nonsensical: to starve is to deny one's body what is necessary to it, in a way that brings about suffering and malfunction. The longer this continues, the greater the risks of catastrophic malfunction become - most notably heart failure. Nonetheless, I was able to pretend to myself that because I never went to sleep hungry, that because I ate lots of chocolate every night, and was able to keep working and keep cycling and walking, I was not heading for death. For me, the ultimate proof of strength would not have been to die: despite my depression, I rarely felt that I wanted to die, and suspected that death from anorexia would probably not be the instantaneous event of fatal heart failure, but rather a long and messy process involving hospitals and intravenous drips and despair. For me, then, strength, control, purity, and bravery lay in keeping eating enough to keep my academic studies on track, my body minimally functional, the rest of life minimally intrusive so as not to waste energy on things that were meaningless to me. Of course all this was immensely self-deluded, but there was also a fragment of truth in it: the late-night feats of bread, lettuce, margarine, cereal, and chocolate were sufficient to sustain life over years if not decades, and made it possible for anorexia to retain its grip on me until I recovered, rather than bulimia or binge eating taking its place.
As well as eating more than many people with anorexia, I allowed myself foods that many anorexics never do: chocolate, biscuits, ice cream, custard, blancmange, pastries, etc. etc. These were all eaten in strictly measured quantities, preceded by lettuce and boiled vegetables, bread, and cereals, at the end of a day of fasting, but they were allowed, indeed required. Eating slightly less than my daily allowance was more repugnant an idea to me than eating slightly more; I had the superstitious conviction (not entirely unfounded) that if I didn't eat 'enough' (i.e. exactly the same as always), I wouldn't be able to sleep, or keep going at all. I loved chocolate in particular so much that I dreamt all day of the delight it would give me when it was finally time for it, and eating it was legitimate, because I'd been so hungry for so long beforehand. This is not to say that my diet wasn't extremely monotonous, and some months before I finally embarked on treatment, and having been vegetarian for more than 15 years, I became aware of powerful cravings for meat (along with those for salt and sugar), and would ask my family to buy steaks so that I might try a bit of them - and I loved the crispy salty fat just as much as the flesh. Responding to these sorts of cravings, or preventing them through a diet that at least includes all the major macronutrient groups, makes an inadequate diet more tenable for longer - and this may, of course, be a good or a bad thing, preventing not only drastic negative changes but also the distress that can lead to recognition and recovery.
Some sufferers from anorexia do want to die. In a recent study, about 7% of the 'restricting subtype' of anorexia reported at least one attempted suicide, but this figure was much higher for those with purging and binge-eating, perhaps due to the greater sense of being 'out of control' in these conditions: 26% and 29% respectively, yielding an average of 17%. If you don't want to die an anorexic, and you don't want to develop another eating disorder, one day you will have to recover. But there's a paradox here, for perhaps the most obvious danger period for the transition from anorexia to binge eating or bulimia comes in the initial refeeding phase. As the previously habitual and comprehensible hunger of gradual starvation give way to the frightening depths of hunger in response to increased availability of nutrients, it's the easiest thing in the world to give in to that desperate desire of one's whole body for more, more, more - too much, too soon. But doing so not only brings with it cardiac risks of its own; it makes falling into uncontrollable eating almost inevitable, which leads to feelings of disgust, self-loathing, and panic.
Nothing is stable at this stage in recovery; nothing quite makes sense; no response seems justified. But somehow, in this first phase, one thing has to be achieved: adhering to a plan. If you've decided to eat 500 calories a day more, this is precisely what must be done. However tempting it is to believe that one should respond flexibly to one's appetite, that one should 'cash in' on this new intensity of hunger to gain more weight more quickly, however perverse it seems to stay desperately hungry, in the initial weeks and maybe months this is the only thing that will work. At some later point it should become clear that one is able to be a bit more flexible as regards the measurement of those (say) 500 calories; I noticed, for instance, that I was being more experimental with my choices of extra food, and not weighing out the amounts, but guessing. This made it possible gradually to stretch the concept of '500' to denote, instead, 'a small meal' or 'two snacks'. In a very gentle, unthreatening manner, it may thus become possible to approach less dysfunctional, and inadequate, eating patterns without feeling control is being lost (even though that 'control' is of course a complete illusion), and without trying to regain normality all at once.
In these exploratory days of early to mid-recovery, a good deal of mental effort is required to counter the deep-rooted conviction that, for instance, to eat more (even if in a planned manner) is to be weak and uncontrolled. Aside from the error inherent in this belief - control is not control if it is exerted compulsively - it is precisely this sort of thinking that initiates the rapid spiral of physiological and cognitive responses that constitute bingeing (whether or not followed by purging). For instance, this belief leads to the conviction that having eaten more, deliberately or compulsively, constitutes a loss of control and a personal failure, so that once a small 'transgression' has occurred, there is no point in trying to be 'controlled' at all any more, recklessness sets in, all 'rules' are abandoned, and a binge takes place, leading to all the negative self-assessment that inevitably follows.
I've only ever binged once, so I can't speak with a great deal of authority on it, but I will always remember the frenzy with which, aged 16, I ate an entire 125g bar of milk chocolate very quickly when alone in the house one afternoon, and the deep helplessness and self-directed disgust that emerged as soon as the eating was over, and the failed attempt to stick my fingers down my throat and vomit it away, and the deception I very easily practised that evening, so as to go to bed early enough to miss the family dinner. This illustrates the point, too, that not all binges are objectively excessive; a binge can be subjective (Fairburn, 2008: 10-11, 14), that is to say that the total calories consumed may not be terribly great (less than 700 in my case). Hence there is a continuum rather than a dichotomy between 'acceptable' and 'unacceptable', or 'normal' and 'excessive' eating. The judgement made about where on the scale a given episode lies depends very much on relative quantities (i.e. the dietary context in which it occurs) and mental clarity and equilibrium (i.e. the cognitive context). A 'binge' need not be perceived as such, and when it is, it becomes one. The 'compensatory' restriction and/or purging that follows makes it much more likely to happen again, so that an unforgiving cycle develops in which there is not even the relative (deathly) stability of starvation, but repeated frequent episodes of distressingly compulsive eating followed by its opposite. Binge eating has been characterised as the attempt to avoid self-awareness, and the same might be said of anorexia. The awareness that one need not live by rules so inflexible that they can be 'broken', and that these are self-created rules that other, healthier, happier people would not espouse, is crucial both in bringing bingeing to an end, and to avoiding it in the first place.
It is possible to find one's way out of anorexia's two-pronged trap: binge eating / bulimia, or death. There is a third way: recovery. I can't say whether had I eaten less I'd have grown despairing sooner and recovered sooner, or whether I'd only have gone down one of the other routes, but I've tried to give some possible reasons for things having turned out as they did. It's important to recognise that, unless recovery is embraced, there are only those two possibilities. But why choose them when life and health are within reach too?
Thanks to the reader whose question prompted this post.