New research shows that the way we live directly affects the length of our bodies - and our lives.
The research, which is published today in a new book 'The Changing Body' (Cambridge University Press), has been conducted over the past 30 years and confirms that there is a clear link between height and longevity.
By exploring the links between nutrition and economic development in Europe and North America since the early-1700s, the researchers linked the changing size, shape and capability of the human body to economic and demographic change.
The research found that 200 years ago there were substantial differences in height between working-class and upper-class people. For example, in nineteenth-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 école 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. 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.
One of the book's authors, Professor Bernard Harris from the University of Southampton, whose work focused on developments in height, health and mortality in Britain and in Continental Europe, says: "The aim is to describe, analyse and explain changes in height and health in different countries over time. However, we also want to emphasise the ways in which the changes may affect patterns of human development in the future.
"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."
Regional variation also plays its part. Two centuries ago, people in Scotland were 2.3cm taller than those living in southern England, while Norwegians were among the shortest nations in Europe. Today the Scottish, 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 says: "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."