It’s not just a genetic issue: poor nutrition in school-age children can contribute to an average 20cm difference in height between individuals from different countries, according to a new analysis published in the prestigious journal The Lancet.
The report reported that in 2019, the world’s tallest 19-year-olds were in the Netherlands (183.3 cm), while the lowest in East Timor (160.1 cm). The tallest adolescent girls of 19 years old are also from the Netherlands (170.4 cm), while the shortest is in Guatemala (150.9 cm).
The team of scientists analyzed data on more than 65 million children and adolescents between 5 and 19 years old, collected by more than 2000 studies carried out between 1985 and 2019.
The researchers emphasize the importance of monitoring changes in the height and weight of children around the world over time, as this may reflect the quality of food available and how healthy the environment is for young people.
Overall, in 2019, they found that children and youth in central and northwestern Europe (the Netherlands and Montenegro) were the tallest in the world. While the lowest average 19-year-olds lived in South and Southeast Asia, Latin America, and East Africa.
Other relevant data from the report
On average, 19-year-olds in Laos were the same height (162.8 cm) as 13-year-olds in the Netherlands. At 19 years old, girls from Guatemala, Bangladesh, Nepal, and East Timor were the same average height as 11-year-old Dutch girls (152 cm).
The most important improvements in the average height of children in the last 35 years have been seen in China and South Korea. But in many countries in Sub-Saharan Africa, the average height has not changed or has decreased since 1985.
The study also looked at body mass index (BMI), a measure that helps determine whether a person is at a healthy weight about their height. The researchers found that older teens with the highest BMI lived in the Pacific Islands, the Middle East, the United States, and New Zealand.
While the 19-year-olds with the lowest BMI live in South Asian countries like India and Bangladesh. Scientists estimate that broadly speaking, the difference between the countries with the highest and lowest BMI levels is 25 kilos. In some countries, children reached a healthy BMI by age 5 but had a high chance of becoming obese by the time they reached 19 years of age.
While the researchers acknowledge that genetics plays an important role in an individual child’s height and weight, they say that when it comes to the health of entire populations, nutrition, and the environment are key.
They also argue that global nutrition policies focus on children under 5 years of age, but their study shows that more attention should be paid to the growth patterns of older children.
Andrea Rodríguez Martínez, a researcher at Imperial College in London and one of the study leaders, points out that a healthy weight and height in childhood and adolescence have long-term health benefits.
“Our findings should motivate (the implementation) of policies that increase the availability and reduce the costs of nutritious foods, as this will help children to grow in height without gaining excess weight”, she said.
In the opinion of Alan Dangour, a researcher at the London School of Hygiene and Tropical Medicine, this is a unique and powerful analysis. “For the first time, a global analysis focuses on the growth of school-age children and adolescents, and identifies that governments around the world are not doing enough to ensure that children enter adulthood in good health.”