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The Physical Effects of Weight Gain After Starvation

What to expect physically as recovery from anorexia begins.

Key points

  • Many people in recovery from anorexia may develop fluid retention, which can look like fat deposits.
  • Severely malnourished people can develop refeeding syndrome in recovery, which may include muscle weakness, delirium, and convulsions.
  • It can be hard to distinguish between the physiological and the psychosomatic effects of eating more after malnourishment.

Anorexia is about eating as little as possible. What counts as 'possible' varies from sufferer to sufferer: It may be next to nothing, a few calories a day, to induce rapid weight loss and hospitalisation, or it may be enough to keep the disorder perpetuated for years or decades, eating just too little every day to sustain a stable and healthy body weight, but enough to avoid hospital and other crises, so that advanced malnutrition and emaciation are very gradual 'achievements'. As I've described in a previous post, there are ultimately only three options for the person who has anorexia: death, the transition to a related eating disorder such as binge-eating disorder or bulimia, and recovery. (I might now add that the recovery option may be split into two possibilities, namely partial and complete recovery; see this post, on making the decision to get better.)

For many people with anorexia, the first two options don't appeal. Suicidal tendencies are relatively common in anorexia sufferers (Stein et al., 2003)—suicide is an even more common cause of death in anorexia than starvation itself (see also Holm-Denoma et al., 2008)—yet there are many who do not wish to die. They acknowledge that what they are doing may well lead to death, but cannot find it in them to care—or, if they care, to act otherwise.

Many find themselves trapped in the vicious circles and paradoxical amalgams of self-starvation. There's the hunger and preoccupation with food combined with the mental reluctance and the physical complications of eating. There's the 'hunger high' (possibly mediated by neurotransmitters like dopamine and serotonin; see e.g. Ioakimidis et al., 2011; Södersten et al., 2016) alternating or simultaneous with the depressive symptoms (e.g. Keys et al., 1950; Mattar et al., 2011). There's the illusion of self-control that drives the progressive loss of all meaningful control. There's the obsessiveness and mental inflexibility (e.g. Kidd and Steinglass, 2016) that prolonged malnutrition brings with it, making the trap hard to comprehend even as they deepen it. There's all this and much more, and it's no surprise that even seeking, let alone finding, a way out often seems inconceivable.

Forewarned is forearmed

But one day, if this is ever to end, one has to confront the necessity of starting to eat more and translate that necessity into practice. In my posts on 'The day I started eating again' and 'How it feels to eat again' I described the psychological changes that took place as I abandoned the mantra of my own personal 'as little as possible', and told of the extreme hunger that accompanied the 500 kcal increase. (This is often also referred to as hyperphagia; see e.g. Dulloo et al., 1997 on its important role in driving adequate food intake for recovery.) In 'Eating, continued', I mentioned some of the stomach pain and diarrhea that I experienced in the months after the dietary change. This time I want to set out in a little more detail the physical changes that often occur when anyone severely malnourished begins to regain weight—whether they have anorexia or have been malnourished for some other reason.

The more you know when setting out on the journey of recovery, the less likely you are to be deterred from carrying on by unexpected and unexplained difficulties. The early stages of a shift in eating habits may well be frightening anyway, not only psychologically but also physically, and contemplating the possibility of specific side effects of recovery may be uncomfortable. But apprehension at specific possibilities is better than a fear of the limitless unknown.

Throughout my own recovery, I found it a deep comfort to hear from my therapist all the ways in which my own trajectory followed a predictable pattern: that whatever difficult thing I was feeling now, it wasn't mysterious, it didn't throw my recovery into doubt—indeed, it indicated that everything was on track because the old, fragile adaptations were being dislodged. This applies just as much to the physical realm as to the psychological.

Refeeding syndrome

One of the most common fears about beginning to eat more concerns the risk of 'refeeding syndrome', which can occur in the very early stages (the first week or so) of weight restoration. The syndrome consists of metabolic and biochemical disturbances that occur when severely malnourished patients begin to take in more nutrients. Insulin secretion (which lowers blood-sugar levels) is suppressed during fasting and increases again once blood-sugar levels rise in response to increased nutrient intake. This results in increased synthesis of glycogen, fat, and protein, which requires phosphates, magnesium, and potassium, reserves of which are depleted in someone who is malnourished. The uptake into the body's cells of much of the blood's electrolyte content leads to a low level of blood phosphate, which in turn can cause muscle weakness, confusion or delirium, convulsions, and other symptoms, and can lead to death through cardiac failure unless phosphorous supplements are given, either intravenously or orally.

Those most at risk are those who are extremely emaciated, have gone for at least five days with negligible food, or have been vomiting or abusing laxatives (see Abraham, 2008, p. 137). The risk is reduced by ensuring very gradual refeeding to begin with by avoidance of foods high in refined sugar, and ideally by continual monitoring of blood electrolyte levels, fluid balance, and organ function, including cardiovascular health (see Gunarathne et al., 2010).

Medically supervised supplementation may also help: in one study (Ornstein et al., 2003) involving 69 patients with anorexia aged between 8 and 22, who were hospitalised for nutritional rehabilitation, low phosphate levels (hypophosphatemia) were observed in 27.5% of patients: in four patients this was moderate, and in 15 it was mild. Supplementation was given, and the only severe complication was one instance of ventricular tachycardia (high but regular heart rate).

Refeeding syndrome is much less likely in someone whose weight is stable or only gradually dropping, and who eats every day without vomiting. And crucially, as is the case for all the physical complications that may arise during refeeding, the risks have to be weighed up against the risks of remaining malnourished. The greater the malnutrition, the greater the risk of complications during recovery—but also, of course, the greater the risks of remaining ill. Starvation can cause (amongst other things) low blood pressure and poor circulation; osteoporosis leading to possible fractures, deformities, and pain; anaemia; stomach shrinkage, leading to uncomfortable stretching and feelings of fullness when more than a small amount is eaten; increased blood cholesterol levels due to lack of oestrogen; nerve and muscle damage; low glucose levels, which may lead to coma; kidney failure; and death through heart failure (see e.g. Treasure, 1997, pp. 106-7).

The point of enumerating these risks both of recovery and of remaining ill is not to induce a paralysed sense of fear or hopelessness. On the contrary, when confronting the daunting idea of recovery, it's important to bear in mind not just what might happen if you go ahead with it, but what might happen if you don't.

Many people with anorexia never experience any of the extreme symptoms listed above, but all will experience some of the milder ones: over-sensitivity to cold, muscular wastage and weakness, sleep disturbances, a weak bladder and constipation, excess hair growth on the body, amenorrhea (cessation of the menstrual cycle), and so on—not to mention the closely related psychological effects like obsessive thought patterns and behaviours and a fixation on body weight and shape.

Fluid retention, weight gain, and fat restoration

For most sufferers undertaking recovery without in-patient treatment, the complications will be unpleasant but not life-threatening. Many of them may seem to confirm one's worst fears since they involve visible bloating that can look like fat deposits.

Fluid retention can cause edema around the ankles (during the day) and around the eyes (at night), seemingly confirming that recovery will mean nothing but 'getting fat'. (Though it's worth noting that edema can be a feature of starvation as well.) As with all the problems that can arise, it can be reduced by ensuring gradual and systematic refeeding.

Another frightening consequence of fluid retention can be disproportionately rapid weight gain in the first days or weeks of eating even a small amount more, as fluid in the tissues between the body's cells and glycogen stores in the liver and muscles are replenished. (This mirrors the rapid weight loss that can be expected when first embarking on a calorie-restricted diet, which is due mainly to dehydration.)

This rapid weight gain (of around 1-1.5 kilos, or 2-3 pounds) soon drops off, and thereafter a helpful rule-of-thumb formula applies: you can expect a gain of 0.5 kilos (approx. 1 pound) per week for an additional 500 calories per day above maintenance levels. During the early days, it is important not to weigh oneself too often (once a week is plenty), because fluctuations in weight can lead to unnecessary anxiety and distress.

In general, weight fluctuations over the course of the day, and from day to day, aren't negligible, so it's important not to attribute significance to a single reading, but to assess at least three readings, taken across three weeks, in order to draw a conclusion about whether weight gain (or loss, or plateauing) is a trend or just an anomaly. (See my post 'To weigh or not to weigh?' for more on this.) After about three weeks of a consistently followed refeeding plan, fat will start to be deposited, in a thin layer all over the body, serving as insulation and protective padding, and helping restore hormonal balance. Then, gradually, sunken cheeks and the hollows between bones are filled in; later, in women, the buttocks, hips, thighs, and breasts will begin to fill out too (see Lucas, 2004, Ch. 9).

Here it's worth devoting a little attention to the midsection in particular. Any changes around the tummy are especially likely to take into standard anorexic fears, and in one of nature's many ironies, the kinds of changes feared are probably exactly what will happen. First, there's the slowing of digestion (food can take four or five hours to pass through the stomach in a starved person, as opposed to about 1.5 in a healthy person) and the wastage of abdominal muscles during starvation. Bloating and wind, abdominal discomfort, and stomach cramps are likely as the digestive system adapts to larger amounts of food and the muscles involved stretch and strengthen. Avoiding too much insoluble fibre may help at this stage. In the longer term, another cause of noticeable and unwanted changes around the midsection is the body's evolved strategy of depositing body fat preferentially in this area so as to protect the vital organs. This imbalance in fat reserves generally normalised within around a year of reaching one's final stable weight (El Ghoch et al., 2014), and it's important to remember that it serves a purpose and is meant to happen. Like all the rest, it will pass, and is not a reliable indicator of what the recovered state will be. Fat distribution may be a little uneven for the first months, but gradually it will even out. Then the once-skeletal sufferer can start to rediscover what his or her healthy body looks and feels like.

Mind and body

It can be hard to distinguish between the physiological and the psychosomatic effects of eating more—indeed, maybe the distinction is a false one. Sensations of nausea can be heightened by the knowledge of eating more than was once 'allowed', or eating foods that were once 'forbidden'. Keeping one's mind focused on the reasons that contributed to the decision to embark on recovery can help in this regard.

Profound tiredness, whether the need to sleep a lot or feelings of physical weakness or both, may be a direct consequence of the systemic changes initiated as soon as more energy is available to fuel them, and they may result in part from the exhausting process of recalibrating all one's former habits of thought and behaviour: now hunger is no longer something to be ignored at all costs; now self-control has stopped meaning what it used to...

In many cases, it will be impossible to establish the precise extent to which the symptom you're struggling with is primarily a physical feature of the imminent end of malnutrition or a more complex mixture involving psychological apprehension at that ending. But it doesn't really matter, because as long as you keep doing what you need to do to keep the process in motion—i.e., keep eating—all of it will pass with time. The psychological trauma will pass, in tandem with, and thanks to, physical recovery. And your growing mental acceptance and resilience will hasten the physical regeneration by making it easier for you to keep building on your new healing habits around food and exercise and rest.

Ultimately, perhaps the most crucial thing to bear in mind is that the discomfort of these complications is a sign of how damaged the starved body is. The discomfort of fluid retention during refeeding, for instance, is proportional to the extent to which the body is dehydrated, and is a consequence of its being rehydrated again.

There is no way around these physical difficulties, just as there is no way around those of starvation, but the key difference is that the former difficulties are a step on the road towards health, whereas the latter only mark the progress deeper into sickness. You are doing the right thing, and the more uncomfortable it feels, the more strongly that is being confirmed. This certain knowledge makes it all bearable.


Abraham, S. (2008). Eating disorders: The facts. 6th ed. New York: Oxford University Press. Amazon preview here.

Dulloo, A. G., Jacquet, J., and Girardier, L. (1997). Poststarvation hyperphagia and body fat overshooting in humans: a role for feedback signals from lean and fat tissues. The American Journal of Clinical Nutrition, 65(3), 717-723. Abstract here.

El Ghoch, M., Calugi, S., Lamburghini, S., and Dalle Grave, R. (2014). Anorexia nervosa and body fat distribution: a systematic review. Nutrients, 6(9), 3895-3912. Full text here.

Gunarathne, T., McKay, R., Pillans, L., Mckinlay, A., and Crockett, P. (2010). Refeeding syndrome in a patient with anorexia nervosa. BMJ (Online), 340. Abstract here.

Holm-Denoma, J.M., Witte, T.K., Gordon, K.H., Herzog, D.B., Franko, D.L., Fichter, M., ... and Joiner, T.E. (2008). Deaths by suicide among individuals with anorexia as arbiters between competing explanations of the anorexia–suicide link. Journal of Affective Disorders, 107(1), 231-236. Full text here.

Ioakimidis, I., Zandian, M., Ulbl, F., Bergh, C., Leon, M., and Södersten, P. (2011). How eating affects mood. Physiology & Behavior, 103(3), 290-294. Full text here.

Keys, A., Brožek, J., Henschel, A., Mickelsen, O., and Taylor, H.L. (1950). The biology of human starvation. (2 vols). Amazon preview of Vol. 1 here.

Kidd, A., and Steinglass, J. (2012). What can cognitive neuroscience teach us about anorexia nervosa? Current Psychiatry Reports, 14(4), 415-420. Full text here.

Lucas, A.R. (2004). Anorexia nervosa: An optimistic guide to understanding and healing. New York: Oxford University Press. Amazon preview here.

Mattar, L., Huas, C., Duclos, J., Apfel, A., and Godart, N. (2011). Relationship between malnutrition and depression or anxiety in Anorexia Nervosa: a critical review of the literature. Journal of Affective Disorders, 132(3), 311-318. Full text here.

Ornstein, R.M., Golden, N.H., Jacobson, M.S., and Shenker, I.R. (2003). Hypophosphatemia during nutritional rehabilitation in anorexia nervosa: Implications for refeeding and monitoring. Journal of Adolescent Health, 32(1), 83-88. Full text here.

Södersten, P., Bergh, C., Leon, M., and Zandian, M. (2016). Dopamine and anorexia nervosa. Neuroscience & Biobehavioral Reviews, 60, 26-30. Full text here.

Stein, D., Orbach, I., Shani-Sela, M., Har-Even, D., Yaruslasky, A., Roth, D., ... and Apter, A. (2003). Suicidal tendencies and body image and experience in anorexia nervosa and suicidal female adolescent inpatients. Psychotherapy and Psychosomatics, 72(1), 16-25. Abstract here.

Treasure, J. (1997). Anorexia nervosa: A survival guide for families, friends and sufferers. New York: Psychology Press. Amazon preview here.

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