Obesity, overweight and underweight among adults in an urban community in Yemen.

High body mass index (BMI) is an important risk factor for morbidity and mortality, while low BMI is an indicator of undernutrition; both may be concerns in low-income countries. This cross-sectional, primary-care based study aimed to measure the sex and age-specific mean BMI and estimate the prevalence of obesity, overweight and underweight among adults in an urban community in Sana'a, Yemen. A total of 2500 subjects (919 males and 1581 females) were recruited in 2006. The crude mean BMI for all ages was significantly higher in females [23.9 (SD 5.1) kg/m2] than males [21.8 (SD 8.9) kg/m2]. The mean BMI trend was associated with age, with a peak in the age group 35-44 years. Calculated prevalence showed 18.0% of males and 14.6% of females were overweight (BMI > or = 25 kg/m2) and 2.5% of males and 12.4% of females were obese (BMI > or = 30 kg/m2). In contrast a substantial number of subjects were underweight (BMI <18.5 kg/m2): 20.1% of males and 14.6% of females.