Obesity among non-pregnant women in the 36 States and federal capital territory of Nigeria; sub-national variation of a national epidemic

Abstract

Background: Obesity has been viewed as a pandemic, with women of reproductive age disproportionately affected compared to men. While studies have reported National prevalence rates in Nigeria, data on the sub-national variation is scarce. This is important because majority of policies/interventions in Nigeria, are developed/implemented at the sub-national level. This study therefore aimed to investigate the sub-national distribution and variation of obesity among non-pregnant women of reproductive age in Nigeria. Methodology: This was a community-based cross-sectional study, which used secondary data from the Nigeria Demographic and Health Survey (NDHS) 2018. A total of 13,180 non-pregnant women of reproductive age (15 – 49 years) were selected from the 36 states and federal capital territory using a two-stage cluster sampling technique. Obesity was determined using the World Health Organization reference values for adolescents (less than 20 years) and others that were older. Sub-national variation was determined with binary logistic regression analysis using unadjusted and adjusted rates, and adjustment was made for individual, household and community level factors. Results: The mean age of respondents was 29.5 ± 9.7 years and there was mostly an even distribution of respondents across the States. The National prevalence of obesity among non-pregnant women of reproductive age in this study was 28.5%. Anambra (54.6%) and Sokoto (6.9%) States had the highest and lowest prevalence rates respectively, with a range of 47.7%. The burden of obesity was higher among the southern states, compared to the northern states generally. After adjusting for all the commonly reported risk factors, about two-thirds of the states (24) still had a statistically significant variation in the prevalence of obesity, such that Akwa Ibom (OR: 4.5; p<0.001; 95% CI: 2.2, 9.0) and Anambra States (OR: 4.4; p<0.001; 95% CI: 2.2, 8,7) had nearly 5 times higher odds of obesity compared to the reference State (Sokoto). Conclusion: Sub-national variations exist in the prevalence of obesity among non-pregnant women of reproductive age in Nigeria, even after adjusting for commonly reported predictors. There is therefore a need to identify state-level determinants of obesity, with a view to designing state-specific interventions to curb obesity among women of reproductive age in Nigeria.