Ethnic disparaties in the prevalence of overweight and obesity among women and children in high income countries : the case for Aftican migrant women and children

Abstract

Excess body weight in women of child-bearing age can have severe consequences for maternal and child health, including reduced fertility, pregnancy complications, an increased risk of child obesity and increased susceptibility to non-communicable diseases. Black women and children in high-income countries (HICs) have a disproportionately higher prevalence of overweight and obesity compared to other ethnic groups. However, there is a lack of evidence on the weight status of African migrant women and children living in HICs, and on these women’s weight perceptions and perceived risks of overweight and obesity. In the first phase of this thesis, I used systematic review, meta-analysis and framework synthesis methods to explore the weight status of African migrant women and children living in HICs, and the dietary and physical activity (PA) behaviours of African migrant women. Metaanalyses results showed that African migrant women had higher body mass index (BMI) (weighted mean difference (WMD)=1.95 Kg/m2, 95%CI 1.16–2.75) and higher odds of overweight (OR=2.45, 95%CI 1.65–3.63), obesity (OR=2.09, 95%CI 1.41–3.12) and combined overweight/obesity (OR=2.09, 95%CI 1.41–3.12) compared to non-African women from HICs. Children of African migrant women also had higher mean birthweights (WMD=48.71g, 95%CI 4.19g–93.24g), higher odds of overweight (OR=1.50, 95%CI 1.00– 2.24), obesity (OR=2.28, 95%CI 1.37–3.78), combined overweight/obesity (OR=2.08, 95%CI 1.40–3.11) and macrosomia (OR=1.83, 95%CI 1.77–1.89), and lower odds of low birthweight (OR=1.06, 95%CI 0.56–2.02) compared to children of non-African women. Risks of overweight and obesity were higher for women and children from North Africa, while data were lacking for sub-Saharan Africa. African migrant women had bicultural dietary patterns, inadequate intakes of iron, folate, and calcium, excessive sodium intakes, and reduced PA levels. There were data gaps on potential confounders that may influence maternal and child weight status, associations between maternal characteristics and child weight outcomes, and weight-related behaviours of pregnant African migrant women. In the second phase, I explored the weight perceptions of African migrant women living in the UK, their perceived risks of overweight and obesity to themselves and their children, and the sociocultural and migration-related influences of these. Interviews conducted with 23 African migrant women from Nigeria, Ghana and Cameroon were analysed through thematic analysis. Key themes identified were: ‘we are not at risk’, ‘bigger is better’, acculturation, ‘a child cannot be too fat’ and infant feeding as a balancing act. The women’s perceptions were influenced by their understandings and lay interpretations of body weight terms, which differed from mainstream knowledge. Perceived risk factors for obesity included: diet, genetics, childbearing and living the ‘easy life’ in the UK. PA was mostly interpreted as sport or exercise and was not an intrinsic part of their culture. Post-migration changes in weight perceptions included increased knowledge of healthy weight-related behaviours, awareness of unhealthy cultural practices and preference for smaller body sizes (for themselves but not their children). Pregnancy was associated with heightened weight-awareness, while preconception weight was believed to have no influence on women’s health or pregnancy. Midwives and relatives were useful information sources for pregnancy weight, and challenges with weight management in pregnancy included families encouraging weight gain; food cravings; unhealthy food in the UK and unfamiliar dietary advice from midwives. Women tended to disregard weight-related advice from health care providers, while valuing advice from friends and family. This thesis identifies African migrant women and children as high-risk groups for overweight and obesity, and highlights the role of migration and socio-cultural influences on their weight status, behaviours and perceptions. There is a need for culturally-tailored interventions to support weight management in this population, especially taking into account their multicultural identities. Further research and interventions addressing the risk factors and areas of need identified could help prevent further increases in obesity, and contribute towards narrowing the inequality gaps in health outcomes among migrant populations in HICs.