A new global study has found that that optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being, but the advantages of living in cities for children’s growth and development are shrinking across much of the world.
The research, led by a global consortium of researchers and physicians including Kent’s Dr James Bentham, analysed height and weight data from 71 million children and adolescents (aged 5 to 19 years) across urban and rural areas of 200 countries from 1990 to 2020.
In the 20th century, in all but a few wealthy countries, living in cities provided a multitude of opportunities for better education, nutrition, sports and recreation, and healthcare that contribute to school-aged children and adolescents being taller than their rural counterparts. The new study found that in the 21st century, this urban height advantage shrank in most countries as a result of accelerated improvements in height for children and adolescents in rural areas.
While height and BMI has increased around the world since 1990, the researchers found that the degree of change between urban and rural areas varied greatly among different middle and low-income countries, while small urban-rural differences remained stable across high-income countries.
The research highlighted that the issue today is not so much whether children live in cities or urban areas, but whether governments are tackling growing inequalities with initiatives like supplementary incomes and free school meal programmes in lower-income countries.
The trend in sub-Saharan Africa was also a cause for concern. Boys living in rural areas have plateaued in height or even become shorter over the three decades, in part because of the nutritional and health crises that followed the policy of structural adjustment in the 1980s.
Particularly large height gaps between urban and rural boys in 2020 were seen in Rwanda (around 4cm) and in the Democratic Republic of Congo, Ethiopia, and Mozambique – all by 2-3.5cm.
Over time, boys and girls in sub-Saharan Africa also gained weight more rapidly in rural areas than cities, which meant that in some countries they went from being underweight to gaining too much weight for healthy growth.
Dr James Bentham, School of Mathematics, Statistics and Actuarial Science, said: ‘The environment that children grow up in is key to their development and future health. In the past, children living in cities had an advantage in most countries. This is still the case in much of sub-Saharan Africa, but we have found that this benefit has become smaller in general. In fact, in some wealthy western countries, it is now children in rural areas who have healthier upbringings. Policymakers will need to consider these trends when developing interventions.’
Professor Andre Pascal Kengne, from the South African Medical Research Council, added: ‘Rural sub-Saharan Africa is now the global epicentre of poor growth and development for children and adolescents. As the cost of food skyrockets and countries finances get worse due to the COVID-19 pandemic and the war in Ukraine, the rural poor in Africa are at risk of falling further behind.’
The study was funded by UKRI (MRC), Wellcome Trust, the European Union, and a charitable grant from the AstraZeneca Young Health Programme, with support from the Jameel Institute.
‘Diminishing benefits of urban living for children and adolescents’ health’ is published in the journal Nature.