Wellcome researchers tracked height among young adult men and women around the world over a 100-year period from 1914 to 2014.
Women in South Korea and men in Iran have seen the biggest increase in height over this period, growing by an average of 20.2cm and 16.5cm respectively.
Men and women in the UK are around 11cm taller than they were a century ago. Height in the USA has increased by 6cm for men and 5cm for women.
The team also found that:
men from East Timor were the smallest in the world in 2014, with an average height of 160cm
women from Guatemala were the smallest, with an average height of 149cm
the difference between the tallest and shortest countries was about 23cm for men – 4cm more than the height gap in 1914
for women, this gap has remained the same across the century, at about 20cm
the average height of young men and women has decreased by as much as 5cm over the past 40 years in some Sub-Saharan African countries, such as Sierra Leone, Uganda and Rwanda.
How tall we grow is strongly influenced by nutrition and environmental factors, although genetics may also play a role. Children and adolescents who are better nourished and live in healthier environments tend to be taller.
Height may also be influenced by a mother’s health and nutrition during pregnancy.
Mary De Silva, Head of Population, Environment and Health at Wellcome, said the most striking thing was the gap between the tallest and shortest countries. "More research is needed to understand the reasons for this gap and to help devise ways of reducing the disparities in health that still persist globally," she added.