LONDON — A new study is illustrating just how important a balanced, healthy diet is during childhood. Researchers from Imperial College London examined the height and weight of millions of school-aged kids from all over the world. Their analysis shows a staggering 20 centimeter (7.9 inches) height difference between adolescents of the same age living in the tallest and shortest countries.
A child’s height and weight are considered indicators of overall health and quality of diet. In all, researchers analyzed a dataset of 65 million kids (ages five through 19) living in 193 different nations between 1985 and 2019. That work reveals the nearly eight-inch gap between 19-year-olds living in the tallest and shortest countries.
Researchers say the numbers suggest an eight-year growth gap for girls and a six-year growth gap for boys. For example, the average 19-year-old girl in Bangladesh and Guatemala is about the same height as the average 11-year-old girl living in the Netherlands.
The study’s authors stress that their findings clearly show why a healthy diet during school years is so important. Lack of proper nutrition during these formative years can lead to stunted growth and obesity.
How do children around the world measure up?
So, where do the tallest 19-year-olds live nowadays? In 2019, that distinction belonged to central and northwest Europe. Teens living in nations like Denmark, The Netherlands, Montenegro, and Iceland all rank as the tallest on average. Conversely, 19-year-olds living in areas like Papua New Guinea, Guatemala, and Bangladesh come in as the shortest.
The research team noted that many children living in poorer nations show a healthy height and weight around age five, but start to show signs of poor diet (minimal height increases, gaining too much weight) after that.
“Children in some countries grow healthily to five years, but fall behind in school years. This shows that there is an imbalance between investment in improving nutrition in preschoolers, and in school-aged children and adolescents. This issue is especially important during the COVID-19 pandemic when schools are closed throughout the world, and many poor families are unable to provide adequate nutrition for their children,” says Professor Majid Ezzati, senior author of the study from Imperial’s School of Public Health, in a university release.
Throughout the study, many countries in Asia such as China and South Korea showed big improvements in average adolescent height over time. It likely isn’t just a coincidence that such countries have also emerged as economic powers over the same period. In comparison to 1985, the average 19-year-old Chinese boy is now three inches taller. On the other end of that spectrum, average heights among many African nations have worsened over the past few decades.
Balancing between healthy height and healthy weight
Regarding body mass index, 19-year-olds with the largest BMIs live in the United States, New Zealand, the Pacific Islands, and the Middle East. Researchers report the lowest BMIs are in nations including India and Bangladesh.
“Our findings should motivate policies that increase the availability and reduce the cost of nutritious foods, as this will help children grow taller without gaining excessive weight for their height. These initiatives include food vouchers towards nutritious foods for low-income families, and free healthy school meal programs which are particularly under threat during the pandemic. These actions would enable children to grow taller without gaining excessive weight, with lifelong benefits for their health and wellbeing,” says lead study author Dr. Andrea Rodriguez Martinez.
The study is published in The Lancet.