Association of Biomass Fuel Use with Reduced Body Weight of Adult Ghanaian Women: Is it an Example of Reverse Causality?

Abstract

Background: Smoking and ambient air pollution have been associated with body weight. Yet, the association of biomass fuel use with body weight has never been investigated in spite of the combustion pollutants sharing similar constituents with these environmental exposures.Objectives: We therefore examined the effect of biomass fuel use on body weight of adult women to provide insight into the obesity epidemic in Ghana and other sub-Saharan African countries.Methods: Data from the 2014 Ghana Demographic and Health Survey, a nationally representative population-based survey was analysed for this study. A total of 4,751 women who had anthropometric (height and weight) data qualified for inclusion in this study.Results: In linear regression modelling, use of charcoal resulted in 3.08 kg (95% CI: 2.04, 4.12) and 0.81 kg/m2 (95% CI: 0.29, 1.33) reduction in weight and BMI, respectively. Use of wood also resulted in 7.77 kg (95% CI: 6.34, 9.20) and 2.49 kg/m2 (95% CI: 1.77, 3.21) reduction in weight and BMI, respectively. In modified Poisson regression with logarithmic function, charcoal users had 19% (Adjusted Prevalence Ratio [aPR] = 0.81; 95%CI: 0.71, 0.92) and 29% (aPR = 0.71; 95%CI: 0.61, 0.83) decreased risk of overweight and obesity, respectively. Wood users had 37% (aPR = 0.63; 95%CI: 0.51, 0.78) and 61% (aPR = 0.39; 95%CI: 0.29, 0.52) decreased risk of overweight and obesity, respectively.Conclusions: The association of biomass fuel use with reduced body weight and BMI of Ghanaian women observed possibly reflects reverse causality from the weight loss triggering correlates of poor socioeconomic status. Elucidating the causal mechanisms through rigorous study designs is important to understanding the policy relevance of our findings.