A century of children growing taller: how the world pushed back stunting

Stunting – when a child is too short for their age because of chronic malnutrition and repeated illness – still shadows about one in four children under five worldwide, some 148 million in 2022. But step back far enough, and the story is one of remarkable progress.

A team led by economic historian Eric Schneider at the London School of Economics has assembled the longest view yet of the problem, published in BMJ Global Health. By combing through 923 studies of children's heights across 122 countries, some reaching back to the 19th century, and joining them to modern figures from the UN's Joint Malnutrition Estimates, the researchers reconstructed how stunting rose and fell over more than a century.

The headline finding is hopeful: rates that were once high in countries now considered wealthy fell dramatically over the 20th century. Globally, stunting dropped from around 47 percent in 1985 to 22 percent in 2022. High rates, the data makes clear, are not a permanent condition.

What Japan's climb reveals

No case is more striking than Japan. In the early 1900s, more than 70 percent of Japanese children were stunted; today, almost none are. That descent, mapped year by year, offers something rare – a detailed roadmap of how a country escapes widespread malnutrition.

Much of Japan's early progress, the research suggests, came not from food alone but from beating back infectious disease. As piped water spread – in Tokyo, from roughly a third of households in 1920 to 80 percent by the mid-1930s – deaths from gastrointestinal illness fell sharply. Clean water alone may account for a third to nearly half of the drop in child mortality over that period. Better nutrition drove the steeper decline that followed after the Second World War.

A template for today

The comparison the authors draw is deliberate. Some countries with high stunting today sit roughly where Japan stood a century ago – Burundi and East Timor near Japan's 1920s levels, for instance. Their path forward may rhyme with Japan's: clean water, safe sanitation, hygiene, and control of the infections that keep young bodies from absorbing what they eat.

The deeper message of the data is simple and encouraging. Children's health can be transformed within a few generations – and the tools to do it are already known.