Childhood stunting fell dramatically over the 20th century

• Childhood stunting, which affects 150 million children globally, is a result of malnutrition, disease, and poor hygiene, with long-term impacts on physical and cognitive development.
• New historical data reveals that childhood stunting is not inevitable; many countries, including Japan, have successfully reduced rates from over 70% to under 5% over the 20th century.
• Japan’s experience highlights that sustained progress requires addressing both infectious disease and nutritional quality through infrastructure and policy.

Japan’s Historical Path

• Pre-war period (1900–1940s): Stunting rates declined from 70% to approximately 40–45% primarily through managing infectious diseases. The expansion of clean water infrastructure, specifically in cities like Tokyo, accounted for 30% to 40% of the reduction in child mortality.
• World War II: Progress stalled as calorie supplies dropped and nutritional levels plummeted. Research suggests children were able to recover and reach normal adult height later in life when conditions improved, challenging the irreversibility of early-childhood nutritional deficits.
• Post-war period: Japan accelerated its progress, with stunting falling 2.2 percentage points annually. Success was driven by a combination of deworming programs, hygiene education, sanitation improvements, and a diet shift from cereals to high-quality proteins and produce.

Lessons for Modern Policy

• Infectious Disease Control: Countries currently experiencing high stunting rates, such as India or Burundi, should prioritize safe water, sanitation, and hygiene to reduce the parasitic and diarrheal diseases that prevent nutrient absorption.
• Nutrition and Maternal Health: Improving maternal nutrition is essential, as evidenced by the 250-gram increase in average Japanese birth weights between 1900 and 1970.
• Sustained Investment: Japan’s success demonstrates that rapid change is possible, but it requires simultaneous, long-term commitment to public health, school lunch programs, and infrastructure development.