To our knowledge, only a few Iranian studies have investigated factors associated with obesity among men. The aims of the present study were to explore the associations between sociodemographic factors, smoking and obesity in Iranian men and compare these associations between Iranian men and women.

We used data from the National Health Survey in Iran. A generalised estimating equations model included 11 697 men and 14 854 women aged 20–69 years (12 850 households). Body weight and height were objectively measured. BMI was calculated as kg/m2, and subjects were classified into obese (BMI ≥ 30 kg/m2) and non-obese (BMI < 30 kg/m2).

Among men, adjusted obesity OR were 0·62 (95 % CI 0·52, 0·74), 1·09 (95 % CI 0·90, 1·32), 1·003 (95 % CI 1·00, 1·007) and 0·57 (95 % CI 0·40, 0·81) for smokers, married, economic index and active workforce groups, respectively. Using low education as the reference group, the obesity OR for men were 1·06 (95 % CI 0·89, 1·26) and 0·75 (95 % CI 0·57, 0·99) for the moderate and high education groups, respectively. Using rural as the reference group, the obesity OR was 1·87 (95 % CI 1·56, 2·26) for urban men.

Our findings may point towards a better understanding of the social and cultural mechanisms of obesity in Iranian men. The above sociodemographic factors are large contributors to obesity and provide the greatest opportunity for actions and interventions designed for prevention and treatment.