Better living standards lead to humans growing taller, according to new research.
The research also shows that while the Scots used to be taller than the English 200 years ago, they are now shorter.
Professor Bernard Harris, from the University of Southampton, is one of the authors of the study which has examined links between nutrition and economic development with height.
He said: "Our work shows that there have been dramatic changes in child health, as reflected in achieved adult height, over the last 100 years, and other researchers have highlighted the existence of close links between improvements in child health and health in later life.
"These changes have profound implications for developments in later-life health, longevity and economic performance over the coming century. The investments we make in the health of today's children can play a pivotal role in determining the economic wellbeing of future generations."
The study, released in a new book called The Changing Body, explored the links between nutrition and economic development in Europe and North America since the early 1700s. The research found that 200 years ago there were substantial differences in height between working-class and upper-class people.
In 19th century Europe, there were dramatic differences between the heights of poor London boys and boys attending the Royal Military Academy at Sandhurst, between army recruits and students attending the Ecole Polytechnique in France and between the sons of "elite" families and those who grew up in unskilled manual households in the Netherlands.
In the 1780s, the average height of a 14-year-old working-class child was 1.3m, while an upper-class child was "significantly taller" at 1.55m. Prof Harris said: "Today however, as health services, nutrition, sanitation and education have become universal, upper-class children have continued to grow taller, but at a slower rate than working-class children. The difference between the upper and working-class adults has narrowed to less than 0.06m."
The research has also shown that height varies between different regions of the UK and Europe. Two centuries ago, people in Scotland were 2.3cm taller than those living in southern England, while Norwegians were among the shortest nationals in Europe.
Today the Scots, averaging 1.73m for an adult male, are shorter than those living in south-east England at 1.75m, while the Norwegians are the second tallest nation in Europe, surpassed only by the Dutch. Professor Harris said: "Improvements in diet and sanitation in the South-East have outstripped improvements in Scotland, reflecting the broad pattern of economic and social change over the last 200 years."