Canadians still getting taller, but not as fast as others

Canadians like to think that we stand tall on the world stage. But according to the largest ever global study on height, Canucks aren't growing as fast as citizens of some other countries.

Where Canadian men were the fifth tallest in the world in 1914, they were the 27th tallest a century later. Canadian women, sixth tallest at the outbreak of the First World War, were 40th tallest in 2014.

• Why are the Dutch so tall?

It's not because Canadians haven't grown in height over that 100-year period. It's that we haven't grown as much as some others. 

Canadian men, for instance, had an average height of 170.7 centimetres (5-foot-7) in 1914. Average height continued to grow over the next 100 years, topping out at 178.1 centimetres (5-foot-10) in 2014.

But that 7.4-centimetre gain over a century paled in comparison with gains of about 11 centimetres among British and Chinese men and a study-leading 16.5 centimetres among Iranian men.

The situation was much the same for Canadian women. In 1914, the average Canadian woman was 157.6 centimetres (5-foot-2) tall. A century later, the average was up to 163.9 centimetres (5-foot-4) — a gain of 6.3 centimetres.

By comparison, the average South Korean woman was 20.2 centimetres taller, while British and Chinese women gained an average of about 11 centimetres.

World generally grows taller, but at different rates

Why did Canadians fall in the relative height rankings between 1914 and 2014?

 "A combination of two things," said Majid Ezzati, a professor of public health at Imperial College in London and lead researcher.

"[Canada] started taller than elsewhere ... [and hit] a plateau earlier and at a lower level than other countries, for example, those on continental Europe, that continued to grow taller," he said in emailed remarks to CBC News. 

Like Canada, the U.S. saw a similar drop in its relative height rankings. American men, who were third tallest in the world in 1914, were 37th tallest in 2014. American women fell from fourth tallest in 1914 to 42nd tallest a century later.

Researchers, led by scientists at Imperial College, arrived at their findings by gathering a century's worth of height data from almost 200 countries for each year from 1914 to 2014, and calculating average height for 18-year-olds — an age when people tend to stop growing. Results were published in the journal eLIFE.

They scoured hundreds of original sources — everything from military conscription records to epidemiological studies and nutrition surveys.

Among other things, they found that:

• The tallest men in 2014 were in the Netherlands, with an average height of 182.5 centimetres (6 feet).
• The tallest women could be found in Latvia, with an average height of 170 centimetres (5-foot-7).    
• The shortest male population was in East Timor, with an average height of 160 centimetres (5-foot-3).
• The shortest women were found in Guatemala, at 149.4 centimetres (4-foot-11).

The top 10 countries for height for both men and women in 2014 were all found in Europe.

While developed countries saw heights steadily increase over time, some countries in Africa and the Middle East actually saw average heights drop in the past few decades.

In Togo, Swaziland and Sudan, for instance, the height of the average man declined by two centimetres over the past two decades. In Rwanda, the average male's height has dropped by almost five centimetres in the last 40 years. 

Height as health indicator

National height figures are more than interesting statistical data points. While genetics play a major role in how tall people grow to be, height figures can be a good indicator of nutrition and health care. "Children and adolescents who are malnourished, or who suffer from serious diseases, will generally be shorter as adults," the study points out.

"This is important because taller people generally live longer, are less likely to suffer from heart disease and stroke, and taller women and their children are less likely to have complications during and after birth."

Countries with the tallest men in 2014 (1914 rankings in brackets)

1. The Netherlands (12).
2. Belgium (33).
3. Estonia (4).
4. Latvia (13).
5. Denmark (9).
6. Bosnia-Herzegovina (19).
7. Croatia (22).
8. Serbia (30).
9. Iceland (6).
10. Czech Republic (24).

     27. Canada (5)

Countries with the tallest women in 2014 (1914 rankings in brackets)

1. Latvia (28).
2. The Netherlands (38).
3. Estonia (16).
4. Czech Republic (69).
5. Serbia (93).
6. Slovakia (26).
7. Denmark (11).
8. Lithuania (41).
9. Belarus (42).
10. Ukraine (43).

     40. Canada (6)