Obesity levels among women in low- and middle-income countries tend to rise in line with wealth as they purchase more energy-dense foods, but a new UCL study suggests that more educated consumers make better food choices that mitigate this effect.
The study showed that in middle-income countries, obesity levels among women with secondary or higher education are 14-19% lower than less-educated women of similar wealth.
The research, published in PLOS ONE, looked at the relationships between obesity, education and wealth in over 250,000 people across four middle-income and three low-income countries between 2005 and 2010. More educated people are typically wealthier, and this study was the first to isolate the effects of education and wealth to unpick their distinct effects.
Each household's "wealth index" was measured by evaluating their possessions, housing situation and access to basic amenities. Based on these criteria, they were divided into five wealth brackets on a scale of 1-5, from richest to poorest, in each country.
The middle-income countries examined were Egypt, Jordan, Peru and Colombia. In Egypt, where 43% of the 32,272 women surveyed were obese, the effect of wealth on obesity was reduced as education levels increased. The increased risk of obesity associated with a rise in wealth bracket was 39% for women with primary education or below, 25% for women with secondary education and only 2% for women with higher education.
"For the first time, we have studied the interaction between wealth and education and found that they have fundamentally different effects on obesity," says lead author Dr Amina Aitsi-Selmi, Wellcome Trust fellow at UCL. "As emerging economies are exposed to a flood of calories from the global food market, rising wealth often leads to rising obesity as people buy energy-dense foods.
"Our study suggests that investing in women's education protects against this effect by empowering individuals to look after their health. However, it is not a substitute for good public health systems and the regulation of commercial activity such as the aggressive marketing that puts pressure on individuals to consume unhealthy products and take unnecessary risks with their health."
In the low-income countries of India, Nigeria and Benin, the relationship between education and wealth was more difficult to unpick. In India, where only 2.8% of the 113,063 women surveyed were obese, wealth had a profound impact on the risk of obesity. For each increase in wealth bracket, the risk of obesity increased by 123%.
"The jump in obesity risk that people in low-income countries experience as they become wealthier is likely related to the environment of scarcity," explains Dr Aitsi-Selmi. "The weight of scientific evidence that we have leaves no doubt that the environment we live in is largely responsible for the obesity epidemic."
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