Obesity and its increasing burden have become an urgent health problem all over the world. Benefiting from a national representative sample, the present study aimed to estimate the distribution of body mass index (BMI) levels and its association with metabolic and lifestyle risk factors in an Iranian adult population by sex, age, and geographical distribution.
This study involves a national survey of noncommunicable disease risk factor surveillance (STEPs) in Iran. Through systematic random sampling, in compliance with safety considerations during the COVID-19 pandemic, of the 28,520 adults who gave voluntary consent and included in the study, 27,874 participants completed the questionnaires (step 1), 27,745 individuals were anthropometrically measured (step 2), and 18,119 individuals completed laboratory evaluation (step 3). Anthropometric measurements followed based on standard protocols and by using calibrated instruments.
In 2021, the national prevalence of normal weight, obesity, and overweight/obesity in ≥18-year-old Iranian adults was estimated at 33.61% (95% CI: 32.99–34.23), 24.96% (24.39–25.53), and 63.02% (62.39–63.65), respectively. Compared to women, Iranian men had a lower mean BMI [25.54 (24.95–26.13 vs. 27.6 (27.07–28.12) kg/m2] (
The study reveals a significant difference between the prevalence of obesity in male and female participants and between different regions of the country. These findings will help policymakers, clinicians, and researchers to more accurately estimate the obesity/overweight problem and to implement more effective interventional programs to promote strategies of prevention and control of weight gain.