Why Japan's average height stopped growing while Korea, China surged

Japan’s average height has barely changed since the 1990s, while Korea and China have surged ahead. Researchers and media reports cite nutrition, maternal nutritional status and lack of sleep as possible factors. NCD-RisC data show 19-year-old Japanese males averaged 172.1 centimeters in 2019, versus 175.5 in Korea and 175.7 in China. Japan’s 17-year-old male student average was 170.8 centimeters in 2024, nearly unchanged from 170.7 in 2000.

In 1985, Japan led the three countries in average height for 19-year-old males at 170.4 centimeters, compared with 168.7 centimeters in Korea and 167.6 centimeters in China.

Over the next 35 years, estimated average height for 19-year-old Chinese males rose by 8 centimeters and Korean males by 6.8 centimeters, while Japanese males gained just 1.6 centimeters.

Daily per-capita energy supplies in Korea and China are 760 to 800 kilocalories higher than in Japan, according to U.N. Food and Agriculture Organization statistics cited in the report.

OECD data from 2021 show low-birth-weight infants accounted for 10.2 percent of births in Japan, compared with 7.2 percent in Korea.

A 2010 study cited in the report found Japanese children from birth to age 3 slept 11.62 hours a day, compared with 12.49 hours in China and 11.9 hours in Korea.

Published Sep 21, 2026 5:11 pm KST

Nutrition, pregnancy weight limits, sleep emerge as possible factors

An image generated by ChatGPT

Japan's average height has barely changed since the 1990s, falling behind Korea and China. Researchers and media reports point to a possible combination of factors, including nutrition, maternal nutritional status and a lack of sleep.

In a report by Japanese financial daily The Nikkei on Saturday, it cited data published in the medical journal The Lancet in 2020 by the NCD Risk Factor Collaboration (NCD-RisC) that the average height of 5- to 19-year-olds in China and Korea increased at the world's fastest pace over the past 35 years, but Japan's remained stagnant.

According to the data, the estimated average height of 19-year-old Japanese males in 2019 was 172.1 centimeters and 158.5 centimeters for females. This leaves Japanese 19-year-olds about 3 to 5 centimeters shorter than their Korean and Chinese counterparts, where Korean males averaged 175.5 centimeters and females 163.2 centimeters, while Chinese males averaged 175.7 centimeters and females 163.5 centimeters.

Thirty-five years ago, the reverse was true. According to NCD-RisC estimates, Japan led the three countries in 1985 with an average height of 170.4 centimeters for 19-year-old males, compared to 168.7 centimeters in Korea and 167.6 centimeters in China.

Over the next 35 years, the estimated average height of 19-year-old Chinese males increased by 8 centimeters and Korean males by 6.8 centimeters, while Japanese males saw their height plateau, gaining just 1.6 centimeters. School health data from Japan's Ministry of Education, Culture, Sports, Science and Technology show a similar trend, with 17-year-old male students averaging 170.7 centimeters in 2000 and 170.8 centimeters in 2024.

A chart generated by Gemini

Nutrition, pregnancy weight guidance, sleep examined as possible factors

Researchers point first to nutrition. Data compiled by Japan's National Institutes of Biomedical Innovation, Health and Nutrition show the country's daily per-capita caloric intake declined gradually after 1995 before leveling off.

According to statistics from U.N.'s Food and Agriculture Organization, daily per-capita energy supplies in Korea and China are 760 to 800 kilocalories higher than in Japan. The Nikkei reported that lower vegetable intake and diets deficient in calcium and vitamins among young people may also have contributed.

Maternal health guidelines limiting pregnancy weight gain are another leading factor. OECD data from 2021 show low-birth-weight infants — babies born weighing less than 2.5 kilograms — accounted for 10.2 percent of births in Japan, compared to 7.2 percent in Korea.

The Nikkei pointed out that long-standing guidance intended to limit weight gain during pregnancy to prevent hypertensive disorders may have affected fetal growth. The report also noted that dieting among young Japanese women to keep weight down may have contributed to lower birth weights.

A third hypothesis points to Japanese infants and toddlers getting less sleep. A 2010 study by researchers from the Children's Hospital of Philadelphia found Japanese children from birth to age 3 slept 11.62 hours a day, compared to 12.49 hours in China and 11.9 hours in Korea.

"We cannot draw a firm conclusion because there are no direct data, but shorter sleep duration among Japanese children may be one of several factors affecting later growth," Akifumi Kishi, an associate professor at the University of Tokyo, told The Nikkei.

The Nikkei report prompted discussion in Japan on social media platforms like X, formerly Twitter. Some users speculated without evidence that Japanese men's preference for petite women influenced the trend, in addition to the three factors highlighted in the report.

This article from the Hankook Ilbo, the sister publication of The Korea Times, is translated by a generative AI system and edited by The Korea Times.

自上世纪90年代以来，日本的平均身高几乎没有变化，而韩国和中国则迅速增长。研究人员和媒体报道指出，营养状况、孕妇营养状况和睡眠不足可能是造成这一现象的原因。NCD-RisC数据显示，2019年日本19岁男性的平均身高为172.1厘米，而韩国为175.5厘米，中国为175.7厘米。预计到2024年，日本17岁男生的平均身高将达到170.8厘米，与2000年的170.7厘米基本持平。

1985年，日本19岁男性的平均身高为170.4厘米，在三个国家中排名第一，而韩国为168.7厘米，中国为167.6厘米。

在接下来的 35 年里，中国 19 岁男性的平均身高估计增长了 8 厘米，韩国男性增长了 6.8 厘米，而日本男性仅增长了 1.6 厘米。

根据报告引用的联合国粮食及农业组织统计数据，韩国和中国的人均每日能源供应量比日本高出 760 至 800 千卡。

经合组织2021年的数据显示，日本低出生体重婴儿占新生儿总数的10.2%，而韩国的这一比例为7.2%。

报告中引用的一项 2010 年研究发现，日本 0 至 3 岁儿童每天睡眠时间为 11.62 小时，而中国为 12.49 小时，韩国为 11.9 小时。

发布于2026年9月21日下午5:11（韩国标准时间）

营养、孕期体重限制、睡眠等因素可能影响孕期健康。

由 ChatGPT 生成的图像

自上世纪90年代以来，日本的平均身高几乎没有变化，落后于韩国和中国。研究人员和媒体报道指出，这可能是多种因素共同作用的结果，包括营养状况、孕妇营养状况和睡眠不足。

日本财经日报《日经新闻》周六的一篇报道援引了非传染性疾病风险因素合作组织（NCD-RisC）2020 年发表在医学期刊《柳叶刀》上的数据，指出过去 35 年里，中国和韩国 5 至 19 岁青少年的平均身高增长速度位居世界第一，而日本的青少年平均身高则停滞不前。

根据数据显示，2019年日本19岁男性的平均身高约为172.1厘米，女性约为158.5厘米。这使得日本19岁青少年比韩国和中国的同龄人矮3到5厘米左右。韩国男性的平均身高为175.5厘米，女性为163.2厘米；中国男性的平均身高为175.7厘米，女性为163.5厘米。

35年前，情况恰恰相反。根据NCD-RisC的估计，1985年日本19岁男性平均身高为170.4厘米，在三个国家中排名第一，而韩国为168.7厘米，中国为167.6厘米。

在接下来的35年里，中国19岁男性的平均身高估计增加了8厘米，韩国男性增加了6.8厘米，而日本男性的身高则趋于稳定，仅增加了1.6厘米。日本文部科学省的学校健康数据显示了类似的趋势，2000年17岁男生的平均身高为170.7厘米，预计到2024年将达到170.8厘米。

由 Gemini 生成的图表

营养、孕期体重指导、睡眠等因素均被纳入考量。

研究人员首先指出营养状况是罪魁祸首。日本国立生物医学创新、健康和营养研究所汇编的数据显示，该国人均每日卡路里摄入量在1995年后逐渐下降，之后趋于稳定。

根据联合国粮食及农业组织的统计数据，韩国和中国的人均每日能量摄入量比日本高出760至800千卡。《日经新闻》报道称，年轻人蔬菜摄入量较低以及钙和维生素摄入不足也可能是造成这一现象的原因之一。

限制孕期体重增长的孕产妇健康指南是另一个主要因素。经合组织2021年的数据显示，日本低出生体重儿（出生体重低于2.5公斤）占新生儿总数的10.2%，而韩国的这一比例为7.2%。

《日经新闻》指出，长期以来旨在限制孕期体重增长以预防高血压疾病的指导方针可能影响了胎儿生长。该报道还指出，年轻日本女性为控制体重而节食也可能导致婴儿出生体重偏低。

第三种假设认为日本婴幼儿睡眠时间较短。费城儿童医院的研究人员在2010年的一项研究发现，日本0至3岁儿童每天睡眠时间为11.62小时，而中国为12.49小时，韩国为11.9小时。

“由于没有直接数据，我们无法得出确切的结论，但日本儿童睡眠时间较短可能是影响其日后生长发育的几个因素之一，”东京大学副教授岸明文告诉《日经新闻》。

《日经新闻》的报道在日本社交媒体平台（如X，前身为Twitter）上引发了讨论。一些用户在没有任何证据的情况下猜测，除了报道中提到的三个因素外，日本男性偏爱娇小女性也是造成这一趋势的原因之一。

本文来自《韩国日报》（《韩国时报》的姊妹报），由人工智能生成系统翻译，并由《韩国时报》编辑。