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A new study of ancient European diets finds that for thousands of years, men were more likely than women to have access to protein-rich foods. The study provides the first large-scale quantitative evidence of long-suggested gender-based food inequalities throughout history.

51ÉçÇøºÚÁÏ archaeology professor Michael Richards, along with Rozenn Colleter, from the National Institute for Preventive Archaeological Research (INRAP) in France, and colleagues, analyzed isotopes from more than 12,000 individuals across hundreds of sites in Europe, spanning 10,000 years. Their study, , was published in Proceedings of the National Academy of Sciences Nexus.

Isotopes are chemical markers in human remains that allow researchers to reconstruct past diets. Nitrogen isotope ratios reflect the amount of animal protein consumed, while carbon isotopes indicate the types of plants eaten.

In pre-industrial Europe, nutrient-rich foods such as meat were highly valued and often linked to higher social status. By contrast, diets higher in marine resources or grain, like millet, were typically associated with lower status.

Study results show that dietary inequality changed over time and varied by region, but a consistent gender gap remained. Men were more often among those with the richest diets, while women were more frequently among those with poorer diets.

In early Neolithic farming societies, approximately 10000 to 2000 BC, diets were relatively similar overall, though differences between men and women were still present. Inequality increased during the Bronze Age, between 3300 to 1200 BC, likely reflecting advances in agriculture and the emergence of more complex social hierarchies. Inequality reached its peak in Antiquity between 700 BC to 500 AD, although the gender gap narrowed slightly.

Overall, the study shows that diet is closely tied to social structure and gender, and offers a new way to compare inequality in past populations.

To compare inequality across different regions and time periods, the researchers applied a method from economics known as the interdecile ratio. This approach provides a standardized way to measure how diets differed within populations.

Michael Richards is the director of SFU’s Isotope Laboratory, where he develops new isotope methods to study diet and migration. Using advanced mass spectrometry, his research explores how human diets have varied across time and place.

undertook this research in Richard’s lab as a postdoctoral fellow supported by a Marie Sklodowska-Curie Global Fellowship and collaboration between INRAP, 51ÉçÇøºÚÁÏand Géosciences Environment Toulouse.

We spoke to Professor Richards about his research.

How do you interpret the persistence of the gender gap in diet across such long time periods—even as societies and economies changed?

We think these differences were largely culturally motivated. In earlier periods, animal protein was energetically ‘expensive’ to obtain, and in later periods it often carried higher monetary costs. As a result, it likely became a higher-status food. In many societies, where clear status differences existed between males and females, these higher-status foods may have been preferentially consumed by males.

Are there possible evolutionary effects of thousands of years of inequality between men’s and women’s diets—and in general?

The differences in diets we observed may partly reflect biological factors. For example, females often—but not always—require fewer calories per day than males. However, most of the available data comes from relatively recent time periods rather than early human evolution. This suggests that the differences are likely largely social, shaped by cultural norms that gave males greater access to certain foods, particularly protein-rich animal sources.

Beyond gender differences in protein consumption, what other forms of cultural or social inequality emerged from the data?

We see diet disparities widen over time, with the gap between the highest- and lowest-status individuals increasing based on nitrogen isotope values. Earlier societies show relatively little variation within groups, but this becomes more pronounced over time, especially in the medieval period, where clear dietary differences emerge between upper and lower classes of society.

How did you approach the challenge of analyzing isotope data from more than 12,000 individuals? How was the interdecile ratio used?

It is remarkable that there is so much isotope data out there to allow this kind of large-scale meta-analysis. When I started my career in this field over 20 years ago there were only a few hundred of these kinds of measurements, but now Rozenn and colleagues were able to collate over 13,000 results allowing us to look at these large-scale changes.

A major issue with using nitrogen isotopes as a dietary indicator is that the baseline values differ in different regions, so a nitrogen isotope value of a human eating a vegetarian diet in a hot environment could be the same as someone with a carnivorous diet in a cold region. We used the interdecile ratio to capture variation within sites, measuring the difference between the highest and lowest values. This approach allows comparison across regions with different baselines, because it relies on within-site differences rather than absolute nitrogen values.

Tell us about the capabilities of the mass spectrometer at SFU’s Isotope Lab. How did you use the technology in this study?

We measured some of the samples used in this study in our isotope lab at 51ÉçÇøºÚÁÏwhich is dedicated to isotope research in Archaeology. It is one of the few isotope labs based within an archaeological department in the world, which allows archaeology students access to high-level technology that usually they would not be able to use, as often samples are just sent to commercial labs and the results sent back. This allows our students and researchers to have deep experience with preparing, measuring and interpreting their data, an experience that is not possible in most archaeology or anthropology departments. 

For more:

• Michael Richards’ faculty web page and Research Expertise Engine profile
• The Isotope Laboratory at SFU
• 51ÉçÇøºÚÁÏNews: 51ÉçÇøºÚÁÏstudy traces 10,000 years of dietary inequality in Europe