A new study examining the skeletal remains of over 12,000 ancient Europeans reveals a stark and persistent gap in the foods consumed by different segments of society over the past 10,000 years. By analyzing chemical signatures left in human bones, researchers found that diet varied significantly across social lines, with men consistently gaining greater access to meat and high-status foods across diverse historical periods. The report was published in the journal PNAS Nexus.
The research investigates bone collagen isotopes to trace dietary habits across Western Eurasia and the Mediterranean basin from preagricultural times to the modern era. Stable carbon and nitrogen isotopes act as biological recorders of the foods an individual ate during their lifetime. When humans consume plants or animals, the distinct chemical ratios of those foods become permanently locked into their skeletal tissue. Nitrogen isotopes tend to reflect the intake of animal proteins, such as meat, dairy, or certain fish. Higher nitrogen levels indicate a higher position in the food chain. Carbon isotopes help identify the types of plants consumed, distinguishing between different agricultural crops like millet and native European cereals.
For decades, comparing these chemical markers across different regions has presented a major analytical challenge. Local environments, soil fertilization practices, and climates alter the baseline isotope values in the food web. A high nitrogen value in one region might simply reflect farming techniques rather than a rich, meat-heavy diet. This geographic variation often masks the true scale of inequality or social stratification within an isolated ancient community when compared side by side with a community living hundreds of miles away. The newly published analysis addresses this gap by seeking a unified way to measure the historical depth of food inequality and the specific ways in which biological sex influenced human survival and status.
Bioarchaeologist Rozenn Colleter of the French National Institute for Preventive Archaeological Research led the study alongside researchers from the French National Centre for Scientific Research and Simon Fraser University in Canada. The team compiled and standardized isotopic data from 12,281 adult individuals spanning 393 historical locations and 40 modern countries. Every skeleton included in the database had a confirmed biological sex determined through DNA testing or osteological analysis. The massive sample size allowed the team to look at very broad patterns across a massive timescale.
To bypass the problem of fluctuating local baseline environments, the researchers applied a statistical tool borrowed from economics known as the interdecile ratio. This calculation takes a specific trait and compares the group in the top 10 percent with the group in the bottom 10 percent. In modern economics, this is used to measure income disparities. In this archaeological study, it was used to measure isotopic disparities.
By assessing only the highest and lowest extremes of consumption within a single village or burial site, the team established a relative inequality score for each specific settlement. This effectively canceled out the variations caused by local soil or climate. They then aggregated these localized scores across the entire 10,000-year timeline to map how dietary divisions evolved. To ensure their metrics reflected only socioeconomic or gender differences, the team isolated sites located far inland to control for the skewed nitrogen ranges introduced by regular marine fish consumption.
The statistical timeline indicates that dietary disparity fluctuated in tandem with shifting social structures rather than following a steady upward progression. During the Neolithic period, when early farming took hold, societies exhibited highly homogenous diets. The gap between the most and least enriched diets remained quite narrow compared to later eras. Despite this relative equality, the data indicates early disparities in protein access favoring men, an occurrence that confirms observations from modern anthropological studies of subsistence communities.
As Europe moved into the Bronze Age, the arrival of new crops like millet and the rise of complex political systems coincided with a sharp expansion in dietary inequality. Disparities in who had access to premium food peaked during the Iron Age, Antiquity, and the Late Middle Ages. During the Bronze Age and Iron Age periods, carbon isotope differences grew significantly, reflecting a divide between people consuming native crops and those consuming newly introduced cereals. Skeletons from Antiquity show a slight drop in carbon isotope variations, which the researchers attribute to a widespread rejection of millet cultivation across the Roman Empire in favor of wheat.
Through all these historical eras, the biological evidence points to persistent dietary inequalities linked to sex. Males were consistently overrepresented in the top 10 percent of nitrogen and carbon isotope values, pointing to greater access to animal proteins and sought-after crops. Females, by contrast, dominated the lowest percentile. Because the scale of these differences fluctuated widely by period and region, the researchers conclude they reflect cultural practices, social status constraints, and food taboos rather than inherent metabolic differences between male and female bodies.
In some periods, such as the Bronze Age, dual layers of inequality appeared in the data. Some lower-status men consumed higher amounts of millet but less meat, while females faced restricted access to both meat and millet regardless of their social rank. In later periods, such as the Middle Ages, the reintroduction of fish into the daily diet driven by religious practices added another layer of dietary segregation. These patterns suggest that changing agricultural technologies and the consolidation of wealth created distinct culinary boundaries based heavily on class and biological sex.
A primary challenge in interpreting these isotopic patterns lies in the inherent biases of the archaeological record. The database contains a heavily skewed sex ratio, featuring significantly more male skeletons than female skeletons across most time periods except for the Neolithic. This imbalance likely stems from historical burial practices that favored male preservation or modern excavation sampling that targeted graves with abundant artifacts, which are often associated with wealthy male burials.
The reliance on binary biological sex determinations limits the ability to explore more complex gender dynamics that may have existed in these early societies. The interdecile ratio also cannot completely eliminate the background interference created by uneven farming practices. For example, localized soil manuring within a single village can artificially inflate nitrogen levels in specific crops, making some individuals appear to have eaten more meat than they actually did.
Future research will require steady additions of data from historically underrepresented regions and early preagricultural hunter-gatherer sites to clarify exactly when these persistent dietary divides first took root in human history. Expanding the data set will help scientists untangle the specific biological and cultural mechanisms that drove prehistoric inequality.
The paper, “Dietary inequality marker reveals 10,000 years of gender and cultural disparity in Europe,” was authored by Rozenn Colleter, Klervia Jaouen, Dominique Garcia, and Michael P Richards.