South Koreans experienced one of the largest height increases of any population on Earth over the past century. South Korean women gained roughly 20 cm (about 8 inches) in average height, the single largest increase recorded globally, while South Korean men grew by about 15 cm. A century ago, Korean women ranked among the five shortest female populations in the world. Today they sit in the top third of tallest women worldwide, and both men and women are now taller on average than their Japanese and Chinese counterparts.
That transformation didn’t happen because of a sudden genetic shift. It happened because the environment South Koreans grew up in changed dramatically in a very short time.
Koreans Weren’t Always Tall
For centuries, Korean heights barely budged. Skeletal remains from tombs spanning the 15th through 19th centuries show that men during the Joseon dynasty averaged about 161 cm (5’3″) and women about 149 cm (4’11”). Those numbers held remarkably steady for hundreds of years. The sharp upward climb in stature only began at the start of the 20th century and accelerated after the Korean War, tracking closely with the country’s rapid industrialization and rising standard of living.
Nutrition Changed Everything
The single biggest driver of South Korea’s height surge is diet. In the decades following the Korean War, South Korea transitioned from a largely agrarian economy with widespread food insecurity to one of the world’s wealthiest nations. That meant children grew up with consistent access to sufficient calories, and critically, to more protein.
Animal protein intake has climbed steadily across generations. Among Koreans aged 19 to 29, animal-based protein now makes up about 57% of total protein consumption, compared to roughly 46% for those aged 50 to 64. Younger Koreans eat a diet far richer in meat, eggs, and dairy than their parents or grandparents did. Milk became a staple of childhood nutrition through school milk programs, though fresh milk consumption has started declining in recent years as birth rates drop and the school-age population shrinks.
Protein availability during childhood is one of the strongest environmental predictors of adult height. When children get enough protein and calories during key growth windows, particularly in early childhood and adolescence, they reach more of their genetic height potential. Generations of Korean children who grew up malnourished simply couldn’t do that.
Economic Growth Fueled the Change
South Korea’s GDP growth story is unusual. The country went from one of the poorest in the world in the 1950s to an OECD member economy in a single generation. That kind of compressed development creates conditions for rapid height gains: better food, better sanitation, better healthcare, and lower rates of childhood illness (since infections during early life can stunt growth).
Interestingly, researchers comparing South Korean and Japanese children over 50 years found that South Korea’s height gains were actually larger than Japan’s, even though Japan was wealthier for most of that period and had lower child mortality. The explanation may lie in trajectory: Japan’s economic miracle came earlier but stagnated after 1995, while South Korea started poorer but maintained strong, sustained growth. That continuous improvement in living conditions across successive generations may have compounded the effect on children’s development. Still, researchers note there are no fully convincing differences in income, diet, or lifestyle between the two countries that neatly explain the gap, suggesting the relationship between national wealth and height is more complex than it first appears.
The North-South Korea Divide
The most striking evidence that environment, not genetics, explains Korean height comes from comparing North and South Korea. The two populations share the same genetic ancestry, separated only by a political border drawn in 1945. Yet preschool children raised in North Korea are up to 13 cm shorter and 7 kg lighter than children raised in the South. North Korean women weigh up to 9 kg less than South Korean women.
That gap is entirely environmental. North Korea has experienced chronic food shortages and famine, limited healthcare infrastructure, and far lower economic development. The same gene pool, under different nutritional and economic conditions, produces dramatically different results. This natural experiment makes it clear that South Korea’s height gains are overwhelmingly a story about improved living conditions rather than genetic selection.
Genetics Still Play a Role
None of this means genes are irrelevant. Height is one of the most heritable human traits, with genetics accounting for roughly 60 to 80% of height variation between individuals within a well-nourished population. Korean genome studies have identified at least 15 genetic regions associated with height variation, some of which also show up in studies of children with unusually short stature. But these genetic factors explain differences between one Korean person and another, not why the entire population got taller. Population-wide shifts over just a few decades are far too fast to be driven by changes in DNA. What changed was that better nutrition and healthcare allowed Koreans to express more of the height their genes already coded for.
Growth Hormone Use Is Rising
South Korea’s cultural emphasis on height has also created a booming market for growth hormone therapy. The number of patients receiving growth hormone treatment in South Korea nearly tripled between 2015 and 2020, rising from about 5,800 to over 16,200. Among children and adolescents diagnosed with short stature, the percentage receiving growth hormone prescriptions jumped from 1.9% to 5.7% over just four years. National spending on growth hormone claims more than doubled in the same period, reaching 62.5 billion Korean won (roughly $47 million) by 2020.
Growth hormone therapy is medically appropriate for children with genuine deficiencies, but the rapid expansion in South Korea reflects broader social pressure around height. Growth clinics are widely advertised, and many families pursue treatment for children who are simply shorter than average rather than clinically deficient. This cultural factor doesn’t explain the population-level trend, which is driven by nutrition and development, but it does contribute to individual outcomes at the margins.
How South Korea Compares Globally
Despite their dramatic gains, South Koreans are not the tallest people in the world. That distinction belongs to the Dutch, whose men average about 182.5 cm (just under 6 feet). The tallest women live in Latvia, the Netherlands, Estonia, and the Czech Republic, averaging over 168 cm. South Koreans have, however, outpaced most of East and South Asia. They are taller than Japanese, Chinese, Bangladeshi, and Indian populations on average, with South Asian countries plateauing at heights 5 to 10 cm shorter than those seen in East Asia.
For comparison, the United States was one of the tallest nations a century ago but has since fallen behind many European countries, recording the smallest height gain of any high-income nation over that period. South Korea’s trajectory has been the opposite: starting near the bottom and climbing fast. Whether that climb continues or plateaus, as it has in most wealthy nations, will depend on whether nutritional and health conditions for Korean children continue to improve or have already reached their ceiling.