Are Social Inequalities Widening in Generalised and Abdominal Obesity and Overweight among English Adults?

BACKGROUND Obesity is now more common in lower socioeconomic groups in developed nations, but the socio-economic patterning of obesity has changed over time. This study examines the time trends in the socioeconomic patterning of generalised and abdominal obesity and overweight in English adults. METHODS Data were from core annual samples of the Health Survey for England 1993-2008, including 155 661 participants aged 18-75 years. The prevalence of generalised and abdominal obesity and overweight was reported as crude and age-adjusted estimates. Binomial regression was used to model measures of obesity and overweight with age, sex, survey years, and two indicators of socioeconomic position: Registrar General's Social Class (manual and non-manual occupational groups) and relative length of full time education. Trends in socioeconomic patterning were assessed by formal tests for interactions between socioeconomic position measures and survey periods in these models. RESULTS The prevalence of generalised and abdominal overweight and obesity increased consistently between 1993 and 2008. There were significant differences in the four outcomes between the two socioeconomic position (SEP) groups in men and women, except for generalised and abdominal overweight with social class in men. The prevalence of obesity and overweight across the whole period was higher in subgroups with lower SEP (differences of 0.2% to 9.5%). There was no significant widening of the socioeconomic gradient of most indicators of greater body fat since the early 1990s, except for educational gradient in generalised obesity in men and women (P = 0.001). CONCLUSIONS Substantial social class and education gradients in obesity and overweight are still present in both sexes. However, there is limited evidence that these socioeconomic inequalities have changed since 1993.