New research presented at this year's European Congress on Obesity in Porto, Portugal (17-20 May) shows that lower socioeconomic status is associated with higher body-mass index (BMI) through its effects on distress and subsequent emotional eating. The study is by Jade Stewart and Dr Charlotte Hardman, Department of Psychological Sciences, University of Liverpool, UK and colleagues.
Lower socioeconomic status is robustly associated with obesity; however, the underpinning psychological mechanisms remain unclear. According to a recent theoretical model*, socioeconomic disadvantage increases psychological distress which, in turn, promotes maladaptive coping behaviours, such as emotional eating, and ultimately obesity. Furthermore, resilience (an individual's capacity to cope with stressors and 'bounce back') is thought to moderate the association between socio-economic disadvantage and distress thus providing a protective role. The current study sought to test these predictions.
A total of 150 adults aged 18 to 65 years and from a range of socioeconomic backgrounds reported their income and education level as an indicator of socioeconomic status. Psychological distress, emotional eating, and resilience were assessed using the Depression, Anxiety and Stress Scale, the Dutch Eating Behaviour Questionnaire, and the Brief Resilience Scale, respectively. Self-reported height and weight were also obtained to calculate body mass index (BMI).
As predicted, the data (adjusted for age and sex) indicated a significant indirect effect of socioeconomic status on BMI via psychological distress and increased emotional eating; specifically, lower socioeconomic status was associated with higher distress, higher distress was associated with higher emotional eating, and higher emotional eating was associated with higher BMI. An increase by 1 scale point on the emotional eating scale (scale 1-5) was associated with an increase in BMI of 1.9 kg/m2. Mean BMI at the lowest point on the emotional eating scale was 23.3 kg/m2. At the highest point it was 30.9 kg/m2. However, contrary to prediction, resilience was not found to moderate this effect.
The authors conclude: "These findings provide a novel insight into the relationship between socioeconomic status and obesity, suggesting that it may be partly explained by psychological distress and subsequent emotional eating as a coping strategy. Targeting these maladaptive coping behaviours in response to distress may be a way of reducing obesity in low-income populations."
They add: "One way of doing this would be to teach people to implement more positive coping strategies when they are in a state of distress for example going for a walk instead of eating chocolate."
"The association between low SES and access to cheap energy-dense foods and subsequent obesity is already well-documented. What this study does is to shed light on a psychological explanation for the association between SES and obesity and this has received little consideration in research to date."