Study reveals factors behind rise in obesity in SA women of childbearing age

The rising trend of obesity in South Africa’s women of childbearing age is due to a lack of physical activity and increased consumption of unhealthy food, according to a study by University of Cape Town’s (UCT) doctoral student Mweete Debra Nglazi, who will graduate on 22 July.

Nglazi, from UCT’s Faculty of Health Sciences, used nationally representative data from the 2008–2017 National Income Dynamics Study, 1998 and 2016 South African Demographic and Health surveys, and 2005/06 and 2010/11 Income and Expenditure surveys to assess the prevalence of overweight and obesity changes between 1998 and 2017 for non-pregnant women aged 15 to 49 in South Africa. She also examined the determinants of overweight and obesity.

This study, published in BMC Public Health, found that the percentage of overweight females increased from 51.3% to 60.0%, and obesity increased from 24.7% to 35.2%. “Overweight and obesity prevalence remained higher for older [women] than younger women,” said Nglazi.

“Smoking was inversely associated with being overweight and obese.”

In 1998, women with no primary education and those with secondary education had a higher overweight and obesity prevalence than those with tertiary education. But this pattern was reversed in 2017.

Nglazi said the prevalence of overweight and obesity tended to be higher among women from wealthier socioeconomic backgrounds than their counterparts from less wealthy backgrounds.

“For most women, the prevalence of overweight and obesity in 2017 was significantly higher than the estimate in 1998. Significant predictors of overweight and obesity included increased age, self-identifying with the black African population group, higher educational attainment, residing in an urban area, and wealth. Smoking was inversely associated with being overweight and obese,” she said.

Nutrition transition

South Africa is undergoing a nutrition transition, characterised by an increasing prevalence of overweight and obesity. The finding that overweight and obesity increased over time, said Nglazi, could be due to rapid economic development since the dawn of democracy, urbanisation and increased female labour force participation.

“Working women tend to have low-energy jobs, and mobility is less energy-intensive because of shorter commutes and the use of motorised transportation. Time constraint is a challenge for many women in preparing healthy meals because of long working hours and having greater access to processed foods,” she said.

The study also found that in 2012 and 2014/2015 women having tertiary education, compared to no primary school education, had higher odds of being overweight and obese. In most years, except for 1998 and 2016, the odds of being overweight and obese were higher in women having a secondary education compared to those with no primary school education.

“The odds of being overweight and obese [were] lower in women with a tertiary education compared to those with no primary school education.”

“Those with higher education tend to have less energy-demanding jobs, be more physically inactive, and have sedentary lifestyles. By contrast, we found that in 1998, the odds of being overweight and obese [were] lower in women with a tertiary education compared to those with no primary school education,” she said.

In 1998 and 2017, the study found that women residing in urban areas had higher odds of being overweight or obese than those who resided in rural areas.

COVID-19 impact

Nglazi noted that the COVID-19 pandemic highlighted the importance of caring for obese and overweight people, as they were at a greater risk of death and severe COVID-19.

She said, “Increased public health attention is needed about obesity and its health consequences for this vulnerable population. Efforts are needed across different sectors to prevent excessive weight gain in women of childbearing age, focusing on the risk factors identified in the paper.”