Writing in The Lancet, a group of researchers from Imperial College London introduce a new global survey of 65 million children aged 5-19 years old in 193 countries, showing that poor nutrition during school years may have caused a 20 cm height gap between the tallest and shortest nations.
This difference constitutes an eight-year growth gap for girls, and a six-year growth gap for boys, such that an average 19-year-old in one country is the same height as the average 11- or 13-year-old in another.
The data – collected between 1985 and 2019 – shows that the tallest 19-year-olds reside mostly in northwest and central Europe, while the shortest live primarily in south and southeast Asia, Latin America and East Africa.
During the aforesaid period, the largest improvements were seen in emerging economies, such as China, South Korea and some parts of southeast Asia.
Furthermore, the study found that, in some nations, children had a height and weight in the healthy range at age 5, yet later gained too much weight and only a marginal increase in height.
The researchers say that this is likely because of inadequate access to healthy foods during school years. Highly palatable, high-calorie, but low-nutrition foods are easy to come by and lead to rapid weight gain, while height increases stagnate.
According to Majid Ezzati, senior author on the study, the situation has gotten even worse with COVID-19. As more and more schools enter quarantine, many poor families find themselves unable to ensure a proper diet to their children.
The authors advocate for policies that may help increase the availability and reduce the cost of nutritious foods.
“These initiatives include food vouchers towards nutritious foods for low-income families, and free healthy school meal programmes 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,” said lead author Dr Andrea Rodriguez Martinez.