Men have gained weight and height twice as fast as women in past century, study finds

Stature and physique are prime indicators of health and vitality, while sexual selection also favours men who are better able to protect and defend their partners and offspring against others, researchers say.

Men around the world have gained height and weight twice as fast as women over the past century, a new study has found.

Prof Lewis Halsey at the University of Roehampton and his colleagues used data from the World Health Organization (WHO), overseas authorities and UK records to see how height and weight have changed with living conditions. The latter was measured by the human development index (HDI), a score based on life expectancy, time in education and per capita income, which ranges from zero to one.

Analysis of records from dozens of countries found for every 0.2 point increase in HDI, women were on average 1.7cm taller and 2.7kg heavier, while men were 4cm taller and 6.5kg heavier. This suggests as living conditions improve, both height and weight increase, but more than twice as fast in men than women.

To see whether similar trends played out within countries, the researchers delved into historical height records in the UK where HDI rose from 0.8 in 1900 to 0.94 in 2022. During the first half of the century, average female height increased 1.9% from 159cm to 162cm, while average male height rose 4% from 170cm to 177cm.

“To put this in perspective, 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,” Prof Halsey said.

Writing in Biology Letters in a study titled: “The sexy and formidable male body: men’s height and weight are condition-dependent, sexually selected traits”, the scientists speculate women’s sexual preferences may have fuelled a trend for taller, more muscular men — although in an age of obesity, heavy does not necessarily mean muscular.

Stature and physique are prime indicators of health and vitality, Prof Halsey said, while sexual selection also favours men who are better able to protect and defend their partners and offspring against others.

“Women can find men’s height attractive because, potentially, it makes them more formidable, but also because being taller suggests they are well-made,” said Prof Halsey. 

“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."

The findings build on previous work that found women want taller men more than men want shorter women. But there are downsides to being tall. While taller people tend to earn more, they are also more prone to various cancers, possibly because they have more cells that can accumulate mutations which culminate in the disease.

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 it was consistent with a long-standing idea that females are “the more ecologically constrained” sex because of the demands of reproduction, particularly in mammals where pregnancy and nursing are “energetically expensive”.

The Guardian