Why does the social gradient in health not apply to overweight?

BACKGROUND In developed countries, there is a negative association between socioeconomic status (SES) and a variety of health outcomes, known as the social gradient in health. This is contrasted by a weak, absent or even positive gradient for overweight. The objective of this study was to investigate why overweight does not follow the social gradient. DATA AND METHODS Data from adult respondents to the 2004 Canadian Community Health Survey (cycle 2.2) were used. A series of multivariate models regressing overweight and determinants of overweight on household education and household income were performed, stratified by gender. RESULTS Except for education among women, negative associations between SES measures and overweight emerged. Respondents from higher household income groups reported more meals away from home, compared with those from lower household income groups. In addition, adults in higher-education households were more likely than those in lower-education households to have quit smoking. INTERPRETATION Differences in food consumption patterns and smoking cessation between SES groups may have contributed to the lack of a clear negative association between household education and income and overweight in the CCHS.