Is the burden of overweight shifting to the poor across the globe Time trends among women in 39 low- and middle-income countries (1991-2008)

Background: Overweight prevalence has increased globally; however, current time trends of overweight prevalence by social class in lower income countries have not been fully explored.Methods: We used repeated cross-sectional, nationally representative data from the Demographic and Health Surveys on women aged 18-49 years with young children (n421 689) in 39 lower-income countries. We present overweight (body mass index25 kg m 2) prevalence at each survey wave, prevalence difference and prevalence growth rate for each country over time, separately by wealth quintile and educational attainment. We present the correlation between nation wealth and differential overweight prevalence growth by wealth and education.Results: In the majority of countries, the highest wealth and education groups still have the highest prevalence of overweight and obesity. However, in a substantial number of countries (14% when wealth is used as the indicator of socioeconomic status and 28% for education) the estimated increases in overweight prevalence over time have been greater in the lowest- compared with the highest-wealth and-education groups. Gross domestic product per capita was associated with a higher overweight prevalence growth rate for the lowest-wealth group compared with the highest (Pearson's correlation coefficient: 0.45).Conclusions: Higher (vs lower) wealth and education groups had higher overweight prevalence across most developing countries. However, some countries show a faster growth rate in overweight in the lowest- (vs highest-) wealth and-education groups, which is indicative of an increasing burden of overweight among lower wealth and education groups in the lower-income countries.