Letter to the editor

Relationship between body mass index andweight perception in schizophrenia

In the paper �Accuracy of body image perception and preferredweight loss strategies in schizophrenia: a controlled pilotstudy�, Loh et al. (1) have found patients diagnosed withschizophrenia i) are more likely to be obese and ii) under-estimate their weight to a greater degree than normal controls.These findings are in good agreement with my M.Sc.

research showing that many patients with schizophrenia wereobese and they commonly underestimated their body weight.One hundred and five patients with schizophrenia wererandomly recruited from a psychiatric outpatient clinic inHong Kong. Information of body mass index, weight percep-tion, dietary habit, exercise habit and other weight-controllingbehaviours were collected. The mean age was 41 years and45% of subjects were male. The mean body mass indexwas 25.3 ± 4.4 kg ⁄m2 and 47% of them were obese. Distor-tion of weight perception was present in 54% of subjects (57%of male and 52% of female). Among these subjects, 93% ofmale and 77% of female underestimated their body weight.The mean dietary intake was 2364 kcal in men and 1807 kcalin women. Weight-control behaviours, mainly diet restrictionor exercise, were present in 22% of men and 27% of women.Only 15% of the subjects had more than 3 h of exerciseper week. Binomial logistic regression analysis of the demo-graphic and clinical variables in predicting obesity are listed inTable 1.Studies of weight perception suggest sex variations in

patients with schizophrenia (2) and in the normal population(3). The similar proportion of obese patients with schizophre-nia in our study suggests the generalized importance of obesityin severely mentally ill populations. The younger mean age ofour sample and the lower cut-off point (4) of body mass indexmay represent greater risk of physical diseases among Asians.Weight-control behaviour appears less common in our sampleand few patients with schizophrenia exercise. The sample sizemay limit the inclusion of different variables in our study.Dietary intake and weight perception are factors which maywarrant further investigations.

Edwin LeeDepartment of Psychiatry

The Chinese University of Hong KongHong Kong, China

E-mail: elee@cuhk.edu.hk

References

1. Loh C, Meyer JM, Leckband SG. Accuracy of body imageperception and preferred weight loss strategies in schizo-phrenia: a controlled pilot study. Acta Psychiatr Scand2008;117:127–132.

2. Strassnig M, Brar JS, Ganguli R. Self-reported body weightperception and dieting practices in community-dwellingpatients with schizophrenia. Schizophr Res 2005;75:425–432.

3. Yancey AK, Simon PA, McCarthy WJ, Lightstone AS, Fiel-

ding JE. Ethnic and sex variations in overweight self-per-ception: relationship to sedentariness. Obesity (SilverSpring) 2006;14:980–988.

4. World Health Organization Western Pacific Region, Inter-national Association for the Study of Obesity and theInternational Obesity Task Force. The Asia-Pacificperspective: redefining obesity and its treatment. Sydney,Australia: Health Communications Australia Pty Limited,2000.

This manuscript was presented to Catherine Loh, Ph.D.,UCSD, San Diego, USA, who had no comments to the Letter.

Povl Munk-JørgensenEditor

Acta Psychiatrica Scandinavica

Table 1. Demographic and clinical variables in predicting obesity by logisticregression

B Sig.

Demographic variables Gender (female) )4.393 0.811Age 0.007 0.865Levels of education 0.174

Clinical variables Distortion of weight perception* )2.305 0.001Dietary intake* 0.018 0.003Exercise )0.035 0.313SANS scores )0.019 0.640Types of antipsychotics 0.997Treatment duration 0.016 0.688

Association Gender and dietary intake 0.008 0.386

*P < 0.05.

Acta Psychiatr Scand 2008: 117: 479All rights reservedDOI: 10.1111/j.1600-0447.2008.01191.x

Copyright � 2008 The AuthorJournal Compilation � 2008 Blackwell Munksgaard

ACTA PSYCHIATRICASCANDINAVICA

479