A new study found that men and women are taller today than they were 100 years ago with Dutch men and Latvian women the tallest on the Earth now.

The study published in the eLife journal Tuesday found that South Korean women and Iranian men have shown the biggest increase in height over the century. Iranian men have increased by an average of about 6 inches and South Korean women by nearly 8 inches. The researchers also found that the difference between the average heights of men and women has largely remained unchanged over the 100-year period.

Our height is based on nutrition and environmental factors with an individual’s genetic factors also playing a role. Children and teenagers who’ve fared well in terms of nutrition and were brought up in better environments tend to be taller, the study says. Height is also influenced by a woman’s health and nutrition during her pregnancy. Other studies suggest that taller people have better life expectancy than shorter people, the researchers said.

“This study gives us a picture of the health of nations over the past century, and reveals the average height of some nations may even be shrinking while others continue to grow taller,” lead author Majid Ezzati reportedly said. “This confirms we urgently need to address children and adolescents’ environment and nutrition on a global scale, and ensure we’re giving the world’s children the best possible start in life.”

The study also found that the U.S. which in 1914 boasted of the third tallest men and the fourth tallest women in the world has declined to 37th and 42nd place in these parameters, respectively, in 2014. In fact, the top 10 tallest countries in 2014 for both men and women all belonged to Europe with no English-speaking nation making it to the top 10.

“Our study also shows the English-speaking world, especially the U.S., is falling behind other high-income nations in Europe and Asia Pacific,” Ezzati, a professor at the School of Public Health, Imperial College London, said. “Together with the poor performance of these countries in terms of obesity, this emphasizes the need for more effective policies towards healthy nutrition throughout life.”

The study by the NCD Risk Factor Collaboration, which is a network of health scientists from around the world, reportedly used nearly 1,500 sources that included government health studies and military data to analyze the changes in the height of 18-year-olds across 200 countries over the period of a century from 1914 to 2014.