Men gained weight and grew taller twice as fast as women over the past century, according to a new study. The data, sourced from multiple countries, reveals that height and weight differences between the genders have grown since 1900.
The study, titled "The sexy and formidable male body: men's height and weight are Condition-dependent, sexually selected traits", was published in Biology Letters. It shows men, on average, are taller and heavier than women across the world.
The study found that for every 0.2-point increase in HDI (human development index), women grew, on average, 1.7 cm taller and 2.7 kg heavier, while men grew 4 cm taller and 6.5 kg heavier. This shows that as living conditions improve, men's height and weight increase more than twice as quickly as women's.
The average female height increased 1.9 per cent from 159 cm to 162 cm during the first half of the century, while the average male height rose 4 per cent from 170 cm to 177 cm, the study concluded.
Professor Lewis Halsey at the University of Roehampton and his team analysed data from the World Health Organization, overseas authorities, and UK records to understand how height and weight have changed with living conditions and what affected them.
They used the HDI, a measure based on life expectancy, education levels, and per capita income, to track changes in height and weight. The HDI score ranges from zero to one, reflecting the overall living conditions in each country.
Halsey stated that about one in four women born in 1905 was taller than the average man born in 1905, but this dropped to about one in eight women for those born in 1958.
He further explained that women find men's height attractive because it makes them seem more formidable and suggests they are healthy and well-developed. "As they've grown up, they haven't been affected by the slings and arrows of a bad environment, so they've reached more of their height potential. It's an indicator that they're well-made," said Halsey.
Michael Wilson, professor of ecology, evolution, and behaviour at the University of Minnesota, said the faster increase in male height and weight was "striking". He said the trend aligned with a long-standing idea that females were more ecologically constrained because of the demands of reproduction, particularly in mammals where pregnancy and nursing are "energetically expensive.".
"Investment in greater body size by males appears to be sensitive to nutritional conditions," Halsey said. "When men grow up with more energy-dense food, they grow bigger bodies, to a greater extent than women," he added.
