Height and weight differences between genders widen over 100 years
A new study has revealed that men have experienced a significantly faster increase in height and weight compared to women over the past century. Published in Biology Letters, the research highlights how improving living conditions have disproportionately influenced male physical development.
The study, titled “The sexy and formidable male body: men’s height and weight are condition-dependent, sexually selected traits”, analyzed data from the World Health Organization, national records, and other global sources to measure trends in height and weight. It found that while both men and women grew taller and heavier over the last 100 years, men’s growth rates outpaced those of women.
Key findings
The researchers observed that for every 0.2-point increase in the Human Development Index (HDI), men grew on average 4 cm taller and gained 6.5 kg, compared to women who grew 1.7 cm taller and gained 2.7 kg. The HDI is a measure of living conditions based on life expectancy, education, and per capita income, with scores ranging from zero to one.
Across the first half of the 20th century, the average male height rose 4% from 170 cm to 177 cm, while female height increased 1.9% from 159 cm to 162 cm.
Professor Lewis Halsey from the University of Roehampton, who led the study, explained, “About one in four women born in 1905 was taller than the average man born that year, but by 1958, this dropped to about one in eight.”
Why the gender gap? Evolution and ecological constraints
The researchers suggested that biological and environmental factors played a key role in the widening gap. Halsey noted that men’s height and weight are “condition-dependent” traits, meaning they respond more dramatically to improved living conditions, such as better nutrition and healthcare.
“Investment in greater body size by males appears to be sensitive to nutritional conditions,” Halsey stated. “When men grow up with more energy-dense food, they grow bigger bodies, to a greater extent than women.”
Michael Wilson, professor of ecology, evolution, and behavior at the University of Minnesota, echoed these findings, describing the trend as “striking.” He attributed the slower growth in women to the energetic demands of reproduction, particularly pregnancy and nursing, which he described as “ecologically constraining.”
Social and evolutionary implications
Halsey also noted the evolutionary advantage of increased male height. “Women find men’s height attractive because it makes them seem more formidable and suggests they are healthy and well-developed,” he said. Height can serve as a signal of resilience, indicating that a man has reached his full genetic potential in favorable living conditions.
The findings add to long-standing discussions on how social, environmental, and biological factors shape physical traits differently across genders. With living conditions continuing to improve globally, the researchers suggest the trends in height and weight may persist, further widening the physical differences between men and women.
