11 September 2023
Middle East still has urban height advantage
Published online 3 April 2023
The Middle East is one of several regions where urban living is still developmentally advantageous.
The developmental advantages of urban living have decreased gradually in the 21st century, except for children in Africa, the Middle East, and parts of Asia, where they have amplified, according to a comprehensive new study published in the journal Nature.
The NCD Risk Factor Collaboration, an international group of 1,500 researchers, collected the height and weight data of 71 million individuals from 2,325 population-based studies. They used the data to compare the average height and body mass index (BMI) of successive cohorts of 5- to 19-year-olds in the rural and urban areas of 200 countries from 1990 to 2000.
The results show that the urban height advantage has generally diminished in recent decades. In 1990, children and adolescents who lived in cities were taller than their rural counterparts, with the exception of high-income countries, where the difference was negligible.
By 2020, the urban height advantage became smaller in most countries, and in many high-income countries the pattern had reversed, such that children and adolescents living in cities were slightly shorter than those in rural areas.
Boys in the Middle East, sub-Saharan and north Africa, central Asia, and Oceania bucked this trend, however. In these parts of the world, boys in rural areas did not gain height, and may have become slightly shorter. Hence, the urban height advantage here appears to have been amplified. In these regions, the BMI of urban children also increased slightly.
“The gap in the height of boys in urban versus rural areas stagnated around 1.5cm in the Middle East throughout the past two decades,” says research fellow in health analytics and machine learning, Bin Zhou, of Imperial College London, UK. “This gap also closed for girls in the Middle East.”
Few studies to date have compared the growth and development of children and adolescents in urban and rural environments, but a better understanding of these trajectories could inform programmes and policies that promote healthy growth.
This will be particularly important in years to come, as increasing poverty, the COVID-19 pandemic, and the war in Ukraine make it increasingly difficult for growing numbers of people around the world to gain access to nutrient-rich food.
“Health policies and programmes should be tailored to address the need of boys and girls in both urban and rural areas,” adds Zhou. “For example, nutrition and school meal programmes in rural areas, especially for the poorer population, would be needed to close the growth gap.”
Mishra, A., et al. Diminishing benefits of urban living for children and adolescents' growth and development. Nature https://doi.org/10.1038/s41586-023-05772-8 (2023).