The impact of rising food prices on obesity in women: a longitudinal analysis of 31 low-income and middle-income countries from 2000 to 2014.

Objectives: To examine whether changes in food prices are associated with changes in obesity prevalence among women in developing countries, and assess effect modification by individual socioeconomic status (SES).

Methods: Longitudinal study of country-level food price inflation temporally and geographically linked to anthropometric data on non-pregnant adult women (n = 295,984) in 31 low-income and middle-income countries over the 2000-2014 time period, using separate multivariable multilevel growth models of five SES indicators. Post-estimation analysis computed the relationship between food price inflation and predicted mean probabilities of being obese, by SES.

Results: Rising food price inflation was strongly associated with women's obesity prevalence, and SES consistently modified the relationship. Regardless of indicator used, higher food price inflation was positively associated with obesity among women in top SES categories, but was flat or negative among women in low SES categories, averaging over time. The SES differences were widest across educational strata and were most pronounced when food price inflation was highest. Overall, for every 1-unit increase in food price inflation, predicted mean obesity prevalence was between 0.02 and 0.06 percentage points greater in women of high SES compared to low SES women.

Conclusion: There is a strong link between food price inflation and obesity in adult women in developing countries which is clearly modified by individuals' SES. Greater food price inflation was associated with greater obesity prevalence only among women in higher SES groups, who may be net food buyers most at risk of obesity in low-income and middle-income countries.