BMC Public Health 2006, 6:228 http://www.biomedcentral.com/1471-2458/6/228 Background The prevalence of overweight and obesity is rapidly increasing in developing as well as industrialised coun- tries [1-3]. A previous Cameroonian study in a rural pop- ulation found very little gain in weight with age and very low prevalence of overweight and obesity [4]. However, studies from urban populations in Cameroon have shown that overweight and obesity are increasingly common [4,5]. For example, the estimated prevalence of obesity, based on BMI, was 17.1% in women and 5.4% in men in urban Cameroon in 2002 [4]. The evaluation of fatty mass and definitions of overweight and obesity use a range of approaches, some of which are complex or invasive, and are inapplicable outside of spe- cialised clinical practice to identify candidates for weight management [6-8]. In routine clinical practice and epide- miological studies the most commonly used measure to define overweight and obesity is the Body Mass Index (BMI). In addition, central obesity is measured by increase in waist circumference (WC) or waist-to-hip ratio (WHR) [9]. Increased weight and waist circumference have been shown to be strongly associated with cardiovascular dis- ease risk factors such as diabetes and hypertension in many populations [10-12]. The objective of the Cameroon Burden of Diabetes (Cam- BoD) Project was to carry out an extensive survey in four urban areas of Cameroon, using the WHO STEPS approach [13] to assess the prevalence of cardiovascular risk factors. The present paper aims to provide baseline and reference data on the prevalence and distribution of overweight and obesity, using anthropometric measure- ments in the adult population from four urban centres in Cameroon. Methods Study population The methods used for this study have been described else- where [14]. The Cameroon Burden of Diabetes (Cam- BoD) was a cross-sectional study conducted in 4 urban districts (Yaoundé, Douala, Garoua and Bamenda) of Cameroon. The study used multilevel systematic sam- pling stratified by age group. A population of 23,000 males and females' adults aged 15 years and above were identified in the census from the study sites, and 10,824 individuals were invited to participate. Ten thousand eleven individuals (6,004 women and 4,007 men) from 4,189 households (range 1–20, mean of three participants per household) participated, giving an overall response rate of 92.5%. Each study site contributed approximately 25% of the total sample. The response rate was higher in females and in the lower age groups (< 35 years). The WHO STEPS approach (modified STEP Version 1.3 instru- ment [15]) for collecting surveillance data for non-com- municable diseases was used to collect prevalence data for diabetes, hypertension and their risk factors. Measurements Anthropometric measurements included weight, height, waist and hip circumference. Body weight in light clothes was measured to the nearest 0.1 kg using a Soehnle scale (Soehnle-Waagen GmbH & Co. KG, Wilhelm-Soehnle- Straße 2, D-71540 Murrhardt/Germany) and height to the nearest 0.5 cm using a portable locally manufactured sta- diometers. Subjects stood upright on a flat surface without shoes, with the back of the heels and the occiput on the stadiometer. BMI was identified as weight divided by height squared (kg/m2). Four categories of BMI (≤20, 20– 24.9, 25–29.9, and ≥30 kg/m2) were identified. The cate- gories were selected according to WHO recommendations to define individuals with a healthy weight (BMI 20–25), overweight (BMI 25–29.9) and obese (BMI≥30) [1]. Indi- viduals with a BMI ≤20 kg/m2 were classified as under- weight. Waist circumference (WC), taken midway between the lowest rib and the iliac crest, and hip circum- ference at the level of the greater trochanters was meas- ured to the nearest millimetre using a flexible tape. Men with a waist circumference of <94, 94–101.9 and ≥ 102 cm were classified as normal weight, overweight and obese respectively, while women were classified in the same obesity categories on the basis of WC <80, 80–87.9 and ≥ 88 cm. Waist-to-hip ratios (WHR) were obtained by dividing waist circumference by hip circumference. Men with WHR < 0.90, 0.90–0.99 and ≥ 1.0 were classified as normal weight, overweight or obese respectively, while women were classified in the same categories on the basis of WHR of < 0.80, 0.80 – 0.84 and ≥ 0.85 [1,16]. Sociodemographic factors Sociodemographic factors were assessed using the WHO STEPS instrument. Due to the difficulties in assessing income and profession in the Cameroonian context, the level of education (number of years of schooling, exclud- ing pre-school), was used as the main sociodemographic indicator. The study population was categorised into less than 7 years schooling, 7–14 years and >14 years to corre- spond to primary, secondary and university levels. Data analysis All analyses were conducted using STATA version 6.0 soft- ware [17] and were performed separately for men and women. All analyses were adjusted for the complex sam- pling design. Age-adjusted partial correlation coefficients were calculated to investigate the association between anthropometric variables. Odd ratios were calculated using logistic regression and are presented with 95% con- fidence intervals. Statistical significance was set at P < 0.05 (two-tailed) where relevant. 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