Socioeconomic inequality in food intake and adult obesity in Portugal

Abstract

Objective: To examine socioeconomic inequality in dietary habits and obesity in Portugal, looking at their evolution from 2005/06 to 2014. Methods: Cross-sectional data collected by Statistics Portugal – National Health Survey. Samples used in this study include 18–64-year olds (n=23,049 in 2005/06 and n=10,312 in 2014). The analysis focusses on differences in the prevalence of intake (at main meals) of nine foods across income groups and over time. Multiple logistic regression analysis is adopted to analyse association between socioeconomic factors (income and education) and obesity, controlling for behavioural and demographic characteristics. Results: Mean prevalence (%) in intake of food in 2005-06/2014 – soup (66/59: P<0.01), beans (22/28: P<0.01), meat (80/80), fish (48/46), carbohydrates (88/88), cakes (26/40: P<0.01). Intake increases with income in both periods for salad, fruit, fish and cakes; in 2014, intake decreases for soft drinks. The ratio between intake in highest income group and intake in lowest income group for fish, salad, cakes and soft drinks, changed from 1.24, 1.13, 1.6, 0.9, in 2005/06, to 1.71, 1.37, 1.2, 0.66, in 2014, respectively. Association between income and obesity is significant only in highest income group (OR about 0.78 in both periods). Risk of obesity is lower for secondary and superior education, compared to basic, in both years (OR=0.616 in 2005/06 and OR=0.820 in 2014, for secondary education; OR=0.525 in 2005/06 and OR=0.608 in 2014, for superior education). Conclusions: Differences in dietary habits tended to increase in a decade, favouring the better-off. Socioeconomic inequality in obesity is clearer for education than income and persisted over time.