What are the growth and development differences in urban and rural areas for children and adolescents?

In a recent study published in Nature, researchers assessed the impact of urban living on the development and growth of children.

Background

The maturation and progress of children and adolescents in school are impacted by their nourishment and surroundings within their household, neighborhood, and educational institution. Promoting healthy growth during these specific age ranges serves to solidify progress made and reduce deficiencies from earlier stages of childhood. This reciprocal relationship has lasting effects on an individual’s overall health and quality of life.

The heightened focus on the significance of nutrition and health during the academic years has been accompanied by an assumption that dissimilarities in nourishment and surroundings result in unique growth and development patterns in urban regions instead of rural ones.

About the study

In the present study, researchers compared the average height and body mass index (BMI) of children and adolescents who reside in urban and rural regions.

The researchers utilized 2,325 population-based studies, which collected data on weight and height from a total of 71 million participants across 194 countries. The data employed a Bayesian hierarchical meta-regression model to determine the average BMI and height of individuals between the ages of five and 19 years residing in rural and urban areas across 200 countries.

The study outcomes described the longitudinal trends in BMI and height of children and adolescents of the same age group residing in rural and urban regions of various nations, along with the intergroup disparities. To facilitate comparisons across countries and over time, the team employed age standardization to condense the 15 age-specific estimates, spanning from five to 19 years of age.

Results

In 1990, urban-dwelling school-aged children exhibited greater height than their rural peers. Except for high-income nations, wherein the urban height benefit was either insignificant or a minor rural advantage was observed. In the same year, certain countries in southeast and east Asia, Latin America, sub-Saharan Africa, and central and eastern Europe experienced notable variations in height among children and adolescents residing in urban and rural areas.

The study found a notable difference in height between boys and girls living in urban areas compared to those living in rural areas in the countries under investigation. The range of this difference was between 2.4 to 5.0 cms. Additionally, the probability of urban-dwelling children being taller than their rural counterparts was greater than 0.99.

The disparity in BMI between urban and rural areas remained modest over the three decades, with a maximum difference of less than 1.4 kg/m² across all countries and years and less than 1.1 kg/m² in all except nine countries when considering age-standardized mean BMI. In 1990, the discrepancy in BMI between urban and rural areas was most pronounced in south Asia and sub-Saharan Africa, with certain regions of Latin America following suit. The disparity in BMI between rural and urban areas for both sexes in these countries varied between 0.4 to 1.2 kg/m².

The posterior probability (PP) of children and adolescents residing in urban regions with a higher BMI compared to those residing in rural areas was greater than or equal to 0.89. During that period, the mean BMI levels of male and female individuals residing in rural regions of certain countries were close to, and in certain age groups, even lower than the thresholds indicative of being underweight.

Between 1990 and 2020, variations were observed in the degree to which BMI increased in urban areas as compared to rural regions across middle-income and low-income countries. The disparity in BMI between urban and rural areas exhibited a reduction of up to 0.65 kg m^–2 for both sexes. The PP decrease in the urban-rural BMI gap from 1990 to 2020 ranged between 0.52 and 0.95. These alterations displaced the average BMI of male and female children residing in rural regions of south Asia and sub-Saharan Africa, resulting in a deviation from the underweight range.

Conclusion

The study findings noted that children and adolescents who lived in urban areas exhibited greater height than their rural counterparts, except in some high-income nations. In numerous countries, the urban height benefit experienced a reduction by 2020, and in several high-income western nations, it transformed into a minor urban-centered disadvantage.

In most countries, there was a difference of less than 1.1 kg m^-2 in the age-standardized average BMI of children residing in urban and rural areas. BMI also exhibited a marginal increase in urban areas compared to rural regions within a limited geographical span. The findings indicated that the benefits of urban living in numerous regions across the globe have declined during the current century, while in many parts of sub-Saharan Africa, they have increased.