To examine socio-economic differences in weight-control behaviours (WCB) and barriers to weight control.

A cross-sectional study.

Data were obtained by means of a postal questionnaire.

A total of 1013 men and women aged 45–60 years residing in Brisbane, Australia (69·8 % response rate).

Binary and multinomial logistic regression analyses were performed, adjusted for age, gender and BMI. Socio-economically disadvantaged groups were less likely to engage in weight control (OR for lowest income quartile = 0·60, 95 % CI 0·39, 0·94); among those who engaged in weight control, the disadvantaged group had a likelihood of 0·52 (95 % CI 0·30, 0·90) of adopting exercise strategies, including moderate (OR = 0·56, 95 % CI 0·33, 0·96) and vigorous (OR = 0·47, 95 % CI 0·25, 0·89) physical activities, compared with their more-advantaged counterparts. However, lower socio-economic groups were more likely to decrease their sitting time to control their weight compared with their advantaged counterparts (OR for secondary school or lower education = 1·78, 95 % CI 1·11, 2·84). They were also more likely to believe that losing weight was expensive, not of high priority, required a lot of cooking skills and involved eating differently from others in the household.

Marked socio-economic inequalities existed with regard to engaging in WCB, the type of weight-control strategies used and the perceived barriers to weight control; these differences are consistent with socio-economic gradients in weight status. These factors may need to be included in health promotion strategies that address socio-economic inequalities in weight status, as well as inequalities in weight-related health outcomes.