Dutch men and Latvian women tower over all other nationalities when it comes to height, a new study found.
A century of data compiled in "A century of trends in adult human height," published in eLife journal, revealed that while Europeans were generally gaining in height, people from the Middle East were slowly getting shorter.
The one exception in the region was in Iran, where men had the biggest growth spurts, getting an average of 16 cm, or six inches taller.
In sub-Saharan Africa, height decreased by about five cm for people born after 1960. In the Middle East and North Africa, the trend was much the same, with either a slight decrease in height or barely maintaining the same height.
In Azerbaijan and Uzbekistan, men have also gotten slightly shorter, but women have not experienced the same trend.
Lead scientists from the study said that while DNA was partly responsible for the changes, genetics were not the dominant factor.
"About a third of the explanation could be genes, but that doesn't explain the change over time," Majid Ezzati told the BBC. "Genes don't change that fast and they don't vary that much across the world. So changes over time and variations across the world are largely environmental. That's at the whole population level versus for any individual whose genes clearly matter a lot."
More likely influences can be found in factors like good healthcare, sanitation, and nutrition, as well as the mother's health during pregnancy.
People who were malnourished as children can experience stunted growth as well as other health risks as they get older.
Other research has shown that height is also associated with positive things like earning more money, and appearing more intelligent or attractive.
But being short isn't all bad - there is some evidence suggesting tall people are more susceptible to certain cancers.
Men from East Timor and women from Guatemala were the shortest people overall.
