In a large-scale study, an international team of scientists analyzed a substantial dataset that showcased changes in the height and weight of men from various regions around the world. The researchers discovered that as countries became wealthier and healthier, their populations grew taller and heavier. Notably, men have experienced a growth rate that is twice that of women over the past century.
The researchers examined data from 135,645 individuals (46 percent of whom were men) across 62 countries. This information was supplemented with statistics from Wikipedia and historical records from Great Britain dating back to 1900. The study did not include individuals suffering from obesity.
What Did the Scientists Discover?
The researchers confirmed that there was a clear sexual dimorphism in size during the data analysis, meaning a physical difference between the sexes, with men being taller and heavier than women.
“Our cross-national analysis showed that as social and environmental conditions improve in countries, including a reduction in the overall burden of disease, the height and weight of people increase, but men experience this growth at twice the rate of women, leading to a more pronounced sexual dimorphism in size,” the researchers wrote in their report.
The parameters of both sexes correlated with the wealth level of the country and the health status of its population, measured by the Human Development Index (HDI). The scientists found that height and weight were significantly influenced by quality of life and environmental factors.
But why is this effect much more pronounced in men? According to the team, this may indicate that the male body is more sensitive to living conditions. Perhaps larger bodies require more care and attention. In contrast, the environment likely has a lesser impact on women’s morphology.
The researchers also observed some intriguing variability in metrics between countries. For instance, the range of weight was broader in countries with higher HDI. While the variation in height among men decreased as HDI increased, reported Science Alert.
The scientists suggested that men’s height could serve as a useful indicator of the overall health and well-being of a population. Thus, governments have a relatively straightforward way to measure these variables.
However, the researchers acknowledged that additional, more long-term studies are needed to confirm the patterns identified.
“Our study combined evolutionary biology with indicators of human well-being, providing new insights into how socio-ecological factors and sexual selection shape key physical traits,” the team wrote.
The findings of the study were published in the journal Biology Letters.