Public Health Nutrition

Short Communication

Impact of using national v. international definitions of underweight, overweight and obesity: an example from Kuwait

Mira El-Ghaziria1, Shurooq Boodaia1, David Younga2 and John J Reillya1 c1 c2

a1 Life Course Nutrition and Health, Yorkhill Hospitals, University of Glasgow, Glasgow, Scotland, UK

a2 Department of Mathematics and Statistics, University of Strathclyde, Glasgow, Glasgow, Scotland, UK


Objective To compare the classification of overweight, obesity and underweight using international v. national approaches in Kuwaiti adolescents.

Design Assessment of underweight, overweight and obesity using a national approach (based on Kuwaiti reference data for BMI-for-age) was compared with assessments obtained using three international approaches: the Cole et al. and International Obesity Task Force (IOTF) definitions of thinness and of overweight and obesity (Cole-IOTF); WHO 2007; and US Centers for Disease Control and Prevention (CDC) 2000 reference data and definitions. The degree of agreement between the different methods was assessed using the weighted κ statistic (κw).

Setting Two randomly selected public intermediate schools in Kuwait City.

Subjects A total of 499 10–14-year-old Kuwaiti adolescents.

Results Prevalence of overweight and obesity using Kuwaiti reference data (36·7 %; 95 % CI 32·4, 41·1) was significantly lower than that obtained using international approaches – Cole-IOTF (44·7 %; 95 % CI 40·3, 49·2), CDC 2000 (44·9 %; 95 % CI 40·5, 49·4) and WHO 2007 (50·5 %; 95 % CI 46·0, 55·0) (P < 0·01). All three international approaches showed almost perfect agreement: IOTF v. WHO (κw = 0·82; 95 % CI 0·79, 0·85) and IOTF v. CDC (κw = 0·90; 95 % CI 0·87, 0·92). However, Kuwaiti reference data showed the lowest agreement with the three international approaches, the poorest being with WHO 2007 (κw = 0·54; 95 % CI 0·49, 0·59).

Conclusions Caution should be exercised when using recently collected national reference data and definitions while assessing underweight, overweight and obesity for clinical and public health applications.

(Received December 20 2010)

(Accepted May 04 2011)

(Online publication July 15 2011)


c1 Corresponding author: Email,

c2 Address for correspondence: Physical Activity for Health Research Group, School of Psychological Sciences and Health, University of Strathclyde, Jordanhill Campus, 76 Southbrae Drive, Glasgow G13 1PP, Scotland, UK.