European Eating Disorders ReviewEur. Eat. Disorders Rev. 13, 273–277 (2005)

Patterns of Weekly Weight Gainduring Inpatient Treatment forAdolescents with Anorexia Nervosa

Sarah Davies and Tony Jaffa*Cambridgeshire & Peterborough Mental Health Partnership NHS Trust,Cambridge, UK

Background: There is variation in the literature concerningoptimum weekly weight gain for inpatient treatment of anorexianervosa. The recently published UK National Institute for ClinicalExcellence guidelines recommend 0.5–1.0 kg.Methods: Weight gain was retrospectively compared for 53inpatients admitted consecutively to an NHS adolescent anorexianervosa unit.Results: Mean weekly weight gain achieved was 0.82 kg, with nosignificant differences between patients who did or did not reach atarget weight range, nor those who had or had not had previousinpatient treatment. Variation in mean weekly weight gainbetween patients approximated to a normal distribution. Patientsadmitted with a lower per cent expected BMI gained weightsignificantly faster. Weight gain was initially low, correspondingto low caloric intake, then faster, but tailed off as patientsapproached target weight range.Discussion: Rate of weight gain was within NICE guidelinerecommendations. This still leaves questions as to optimum rate ofweight gain. Copyright # 2005 John Wiley & Sons, Ltd and EatingDisorders Association.

Keywords: adolescent; anorexia nervosa; inpatient; weight gain

INTRODUCTION

There is little evidence to inform the optimum rate ofweight gain for patients admitted to inpatient unitswith a diagnosis of anorexia nervosa. Arguments fora faster rate of weight gain include the desire to keepadmissions brief. In favour of a slower rate are con-siderations of refeeding syndromes (Melchior, 1998;Treasure, Todd, & Szmukler, 1995, p. 370) and, morecommonly, the risk of engendering overwhelming

anxiety and a reduced ability to cooperate withtreatment.

In January 2004, The National Institute for ClinicalExcellence (NICE) (2004) published guidelines forthe treatment and management of anorexia nervosa.This recommends aiming at an average weeklyweight gain of 0.5–1.0 kg in inpatient settings. Thisis, perhaps not surprisingly, roughly in line withthe published literature, although there is a degreeof variation. For example, Lask (1993, p. 133)reported an aim of approximately 0.5–0.75 kg perweek, Lock (1999) stated an aim of 1.0 kg per week,Andersen, Bowers and Evans (1997, p. 350) sug-gested 1.36 kg per week and Touyz, Garner andBeumont (1995) reported an aim of 1.5 kg per week.

Copyright # 2005 John Wiley & Sons, Ltd and Eating Disorders Association.

Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/erv.652

* Correspondence to: Dr Tony Jaffa, The Phoenix Centre, IdaDarwin, Fulbourn, Cambridge CB1 5EE, UK. Tel: 01223884314. Fax: 01223 884313.E-mail: tony.jaffa@cambsmh.nhs.uk

(All these figures were stated with regard to childrenand adolescents, except Andersen et al. (1997),whose recommendations were applied to both ado-lescents and adults.)

Of course, there may be a difference between whatis aimed at and what is achieved. Although Touyzet al. (1995) aimed at the relatively high figure of1.5 kg per week, the mean weight gain actuallyachieved on their ward was 1 kg per week (Touyz,Lennerts, Arthur, & Beumont, 1993, p. 254).

Herzog, Zeeck, Hartmann and Nickell (2004)found that adult patients who were set lower mini-mum weekly weight gain targets (0.5 kg) were morelikely to reach their target weight than were thosewho were set higher minimum weekly weight gaintargets (0.75 kg). Solanto, Jacobsen, Heller, Golden,and Hertz (1994) found an increase in rate of weightgain for adolescent patients when their expectedweight gain criterion was increased from 0.36 kgper 4 days to 0.55 kg per 4 days. This increase in rateof weight gain involved no increase in the complica-tions of refeeding.

Here we report on the pattern of weight restora-tion in inpatients at a National Health Service unitin the UK for adolescents with anorexia nervosa.

The study was designed to answer the followingquestions:

1. What is the mean weekly weight gain for allpatients in the weight restoration phase of treat-ment, i.e. excluding those who have reached theirtarget weight range and should be stabilizing?

2. Is there a difference in the mean weekly weightgain for patients who reach a target weight rangecompared to those who do not?

3. What is the variation in average weekly weightgain between patients?

4. How does the pattern of weight gain change overthe course of inpatient stay?

5. Is there a relationship between average weeklyweight gain and per cent expected BMI atadmission?

6. Is there a difference in the average weekly weightgain for patients who have been readmitted com-pared to patients for whom this is their firstadmission?

SETTING

The Phoenix Centre is a 10-bedded NHS inpatientunit for adolescents with anorexia nervosa. Treat-ment aims to help patients live more successfullywith anorexia nervosa through symptom control

and weight restoration, psychological interventionsto help patients recognize and deal with anorexicthoughts and behaviours and rehabilitation toaspects of normal life.

Refeeding usually commences on a low diet of1200 or 1500 calories. This is reviewed weekly andadjusted depending on weight gain. Typically,patients progress through a set of meal plans, whichincrease by 300 calories per plan, up to a rarelyreached maximum of 4000 calories.

Over the course of the inpatient treatment, a targetweight range is set. Criteria used in determining thisinclude the patient’s BMI (target range tending tohave a lower limit at 95% expected BMI), thepatient’s premorbid weight and weight at whichmenstrual function returns.

Our service states an expectation of 1.0–1.5 kgweekly weight gain on the inpatient unit but oper-ates at aiming for around 1.0 kg per week. The figureof 1.5 kg indicates that patients should not be gain-ing more than this per week. Our experience is thatthis rate tends to be a reasonable compromisebetween on the one hand the need to keep admis-sions from being too lengthy and on the other handavoiding excessive patient anxiety and discomfortand the risk of refeeding syndrome inherent in toofast a weight gain programme.

SUBJECTS

Data were collected from the medical records of 53consecutive inpatient admissions (44 differentpatients) admitted and discharged within a 2-yearperiod (1st March 2002 to 29th February 2004). Therewere no missing data from this time period. For 34patients this was their first inpatient admission forthe treatment of anorexia nervosa. Of the 14 patientsfor whom this was a readmission, five had pre-viously been treated elsewhere and nine at the Phoe-nix Centre. Five patients had two admissions to thisunit in this 2-year period and two patients had threeadmissions. Consequently, these people appearmore than once in the dataset. The mean length ofstay was 16.91 weeks (SD¼ 4.98). Participants ran-ged in age from 11 to 17 years (mean¼ 15.23 years,SD¼ 1.38) and included four males.

METHOD

Retrospective analysis was carried out on the data.The following information had been collected rou-

tinely during treatment:

274 S. Davies and T. Jaffa

Copyright # 2005 John Wiley & Sons, Ltd and Eating Disorders Association. Eur. Eat. Disorders Rev. 13, 273–277 (2005)

� Height and weight at admission� Weekly weight changes throughout inpatient

stay. The time period used for all calculationswas from admission to discharge or to achievingtarget weight range, whichever occurred first.Inclusion of the first few weeks when patientsare on a very low diet and tending to gain littleweight may lead to an underestimate of meanweekly weight gain.

� Target weight range (if applicable)

From this information it was possible to performall other necessary calculations (per cent expectedBMI at admission, length of stay, time from reachingtarget weight till discharge).

Means and standard deviations were calculatedand Mann–Whitney U-tests and Spearman’s rankcorrelations were performed, as appropriate, toanswer the study’s questions.

RESULTS

The mean weekly weight gain was 0.82 kg(SD¼ 0.29) per week.

Thirty-seven patients reached a target weightrange, six patients did not reach a target weight rangeand 10 patients left before a target weight range wasset. The mean weekly weight gain for patients whoachieved their target weight range was 0.85 kg(SD¼ 0.17). This is slightly higher than that forpatients who did not reach their target weight whichwas 0.75 kg (SD¼ 0.5), though the difference is notsignificant (p> 0.05, U¼ 187, Z¼�1.74). There wasmore variation, however, between patients in the

group that did not reach a target weight (SD¼ 0.50compared to 0.17).

The variation in mean weekly weight gainbetween patients (SD¼ 0.30) approximates to a nor-mal distribution (Figure 1). There was no evidence ofa relationship between age and mean weekly weightgain.

Figure 2 shows the pattern of mean weekly weightgain by week of admission. Weight gain tends to bepoor in the first week of admission. In weeks 2–14weight gain varies between approximately 0.7 and1.0 kg per week, then begins to tail off.

A significant negative correlation was foundbetween per cent expected BMI at admission andsubsequent mean weekly weight gain (R¼ � 0.33,p� 0.016, Z¼ � 2.41, df¼ 51). Those patients whowere admitted at a lower per cent expected BMIgained weight faster.

The mean weekly weight gain for patients forwhom this was their first admission was 0.81 kg(SD¼ 0.26). This is not significantly different fromthe mean weekly weight gain for readmissions,which was 0.84 kg (SD¼ 0.36, p> 0.05, U¼ 341,Z¼ 0.33).

Of the 53 patients in this study, one gained 0.5 cmand one gained 3 cm in height during admission,while there were no height changes in the other 51patients.

DISCUSSION

The mean weekly weight gain on this unit was foundto be 0.82 kg, which is less than the rate of weight

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Figure 1. Variation between patients in mean weekly weight gain

Inpatient Weight Gain in Adolescent AN 275

Copyright # 2005 John Wiley & Sons, Ltd and Eating Disorders Association. Eur. Eat. Disorders Rev. 13, 273–277 (2005)

gain aimed at but is within the range recommendedin the NICE guidelines (0.5–1.0 kg) and similar to thefigures quoted in the published literature. While it isof interest to know this, it does not, of course, answerthe question as to what is the optimum weight gain.Our view is that this would be a rate which is fastenough to avoid negative ‘institutionalization’effects of inpatient stay but not so fast as to causeoverwhelming anxiety to the patient nor to resultin an unacceptable risk of refeeding syndromes(Melchior, 1998; Treasure et al., 1995, p. 370). Thesimilarity between the rates reported by differentunits (and included in the NICE guidelines) couldbe explained either as a convergence to what clinicalexperience teaches us is an appropriate level ordue to our learning our trade on the same unitsand therefore continuing what may be unhelpfultraditions.

The rate of weight gain varies over the course ofinpatient treatment, with a slow start reflecting alow initial diet (typically 1200 or 1500 calories perday), followed by a period of faster weight gain,which then tails off as patients approach their targetweight. We would see this as consistent with theneed to reintroduce food gradually and also to reas-sure patients that they will indeed be helped to sta-bilize within an agreed range rather than the fearedendless weight gain.

Neither whether patients had had previous inpati-ent treatment for their anorexia nervosa (this couldbe seen as a proxy for chronicity) nor whether theywent on to reach their target weight range had signif-icant effect on rate of weight gain during inpatienttreatment. It should be noted that although therewas no significant difference in the rate of weight

gain between patients who reached their targetweight and those who did not, there was more var-iation in the group that did not reach a target weight.

Mean weekly weight gain was found to be nega-tively correlated to per cent expected BMI at admis-sion such that those patients admitted at lowerweights gained significantly more weight per weekthan those with a higher per cent expected BMI atadmission. This is a curious finding, and one forwhich we do not have an explanation. One possibi-lity is that as they have more weight to gain, the per-iod during which they are gaining weight mostrapidly (as opposed to starting off eating orapproaching a stabilizing diet and weight) is longer.

CONCLUSION

Weekly weight gain occurs on this unit within therange specified in the NICE guidelines. While thisis encouraging on a local level, the question stillremains, guidelines notwithstanding, as to whatactually is the optimum rate. Further, whether thereis an optimum rate which can be applied globally or,if not, what are the specific criteria which should beused in a given case?

REFERENCES

Andersen, A. E., Bowers, W., & Evans, K. (1997). Inpatienttreatment of anorexia nervosa. In D. M. Garner, & P. E.Garfinkel (Eds.), Handbook of treatment for eatingdisorders (2nd ed., p. 350). New York: Guilford Press.

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Figure 2. Mean weekly weight gain during weight restoration

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Herzog, T., Zeeck, A., Hartmann, A., & Nickel, T. (2004).Lower targets for weekly weight gain lead to better re-sults in inpatient treatment of anorexia nervosa: a pilotstudy. European Eating Disorders Review, 12, 164–168.

Lask, B. (1993). Management overview. In B. Lask, & R.Bryant-Waugh (Eds.), Childhood onset anorexia nervosaand related eating disorders (p. 133). Hove: LawrenceErlbaum Associates.

Lock, J. (1999). How clinical pathways can be useful: anexample of a clinical pathway for the treatment ofanorexia nervosa in adolescents. Clinical Child Psychol-ogy and Psychiatry, 4, 331–340.

Melchior, J.-C. (1998). From malnutrition to refeedingduring anorexia nervosa. Current Opinion in ClinicalNutrition and Metabolic Care, 1, 481–485.

National Institute for Clinical Excellence. (2004). Quickreference guide eating disorders core interventions in thetreatment and management of anorexia nervosa, bulimianervosa and related eating disorders (p. 11). NationalInstitute for Clinical Excellence.

Solanto, M. V., Jacobsen, M. S., Heller, L., Golden, N. H.,& Hertz, S. (1994). Rate of weight gain of inpatientswith anorexia nervosa under two behavioural con-tracts. Pediatrics, 93, 989–991. Abstract retrieved March12, 2004, from Medline database.

Touyz, S. W., Garner, D. M., & Beumont, P. J. V. (1995).The inpatient management of the adolescent patientwith anorexia nervosa. In H. C. Steinhausen (Ed.),Eating disorders in adolescence (p. 254). Berlin: Walter deGruyter.

Touyz, S. W., Lennerts, W., Arthur, B., & Beumont, P. J. V.(1993). Anaerobic exercise as an adjunct to refeedingpatients with anorexia nervosa: Does it compromiseweight gain? European Eating Disorders Review, 1, 177–182.

Treasure, J., Todd, G., & Szmukler, G. (1995). The inpatienttreatment of anorexia nervosa. In G. Szmukler, C.Dare, & J. Treasure (Eds.), Handbook of eating disorders:Theory, treatment and research (p. 370). Chichester: JohnWiley & Sons.

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