Dutch men and Latvian women are the tallest on the planet, according to the largest ever study of height around the world.
The research group, which included LJMU’s Dr Lynne Boddy, conducted the study using data from most countries in the world, tracking the height of young adult men and women between 1914 and 2014.
Among the findings, published in the journal eLife, the research revealed South Korean women and Iranian men have shown the biggest increases in height over the past 100 years. Iranian men have increased by an average of 16.5cm, and South Korean women by 20.2cm.
The height of men and women in the UK has increased by around 11cm over the past century. By comparison, the height of men and women in the USA has increased by 6cm and 5cm, while the height of Chinese men and women has increased by around 11cm and 10cm.
The research also revealed once-tall USA had declined from third tallest men and fourth tallest women in the world in 1914 to 37th and 42nd place respectively in 2014. Overall, the top ten tallest nations in 2014 for men and women were dominated by European countries, and featured no English-speaking nation. UK women improved from 57th to 38th place over a century, while men had improved slightly from 36th to 31st place.
The researchers also found that some countries have stopped growing over the past 30 to 40 years, despite showing initial increases in the beginning of the century of study. The USA was one of the first high-income countries to plateau, and other countries that have seen similar patterns include the UK, Finland, and Japan. By contrast, Spain and Italy and many countries in Latin America and East Asia are still increasing in height.
Furthermore, some countries, particularly those in sub-Saharan Africa, North Africa and the Middle East have even seen a decline in average height over the past 30 to 40 years.
Dr Lynne Boddy, of LJMU’s School of Sport and Exercise Sciences, commented: “How tall we grow is strongly influenced by nutrition and environmental factors, although an individual’s genetics also play a role. Children and adolescents who are better nourished and live in better environments tend to be taller, and height may also be influenced by a mother’s health and nutrition during pregnancy. It has lifelong consequences, for example, some research suggests people who are taller tend to live longer, gain a better education and even earn more. However, being tall may carry some health risks, as studies have linked height to a greater risk of certain cancers including ovarian and prostate. Tracking height and other markers over time helps us to understand population changes and how these factors may influence health moving forwards.”
Professor Majid Ezzati from the School of Public Health at Imperial, who led the research, said: “This study 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, which was co-founded by the Wellcome Trust and the Government of Canada, generated national and global media coverage in The Guardian, Financial Times, Daily Mail, BBC, Sky News, ABC (Australia), CBC (Canada) and CBS News (US), among others. The full report is available to read on eLife.