Background
Low- to middle-income countries (LMICs) are believed to be characterized by the coexistence of underweight and overweight. It has also been posited that such coexistence is appearing among the low socioeconomic status (SES) groups.

Methods
We conducted a cross-sectional analysis of nationally representative samples of 451321 women aged 20–49 years drawn from 57 Demographic and Health Surveys conducted between 1994 and 2008. Body Mass Index (BMI in kg/m2), was used to define underweight and overweight following conventional cut-points. Covariates included age, household wealth, education, and residence. We estimated multinomial multilevel models to assess the extent to which underweight (BMI<18.5 kg/m2) and overweight (BMI=25.0 kg/m2) correlate at the country-level, and at the neighborhood-level within each country.

Results
In age-adjusted models, there was a strong negative correlation between likelihood of being underweight and overweight at country- (r = -0.79, p<0.001), and at the neighborhood-level within countries (r = -0.51, P<0.001). Negative correlations ranging from -0.11 to -0.90 were observed in 46 of the 57 countries at the neighborhood-level and 29/57 were statistically significant (p=0.05). Similar negative correlations were observed in analyses restricted to low SES groups. Finally, the negative correlations across countries, and within-countries, appeared to be stable over time in a sub-set of 36 countries.

Conclusion
The explicitly negative correlations between prevalence of underweight and overweight at the country-level and at neighborhood-level suggest that the hypothesized coexistence of underweight and overweight has not yet occurred in a substantial manner in a majority of LMICs.