A project looking at the history of crops in prehistoric China has identified differences in regional diets and changes over time, which may be connected to varying cooking practices in these areas.
The study, carried out by researchers from Washington University, was recently published in the journal PLOS ONE (https://doi.org/10.1371/journal.pone.0240930). Using existing stable carbon-and nitrogen-isotope data from 2,448 human remains from 128 sites across China, they analysed what these individuals were eating and how dietary patterns changed from 6000 BC to AD 220.
Isotopic analysis revealed evidence of a north/south divide in diets between 6000 and 2000 BC, with people in the Loess Plateau predominantly eating millet, while those further south in the region around the Yangtze and Huai rivers had diets of rice combined with a variety of fruits, nuts, and tubers. It is believed that these differences were connected to environmental conditions, as millet is best suited to the semi-arid conditions of the Loess Plateau, but an aquatic plant like rice would have flourished in the wetlands of the Yangtze–Huai region.
Signs of an east/west division in diets emerged around 2,000 BC, when wheat and barley were introduced from south-west Asia. These new crops were adopted quickly as staple foods in western China, but took much longer to be accepted by people in central China, particularly in the area around the Loess Plateau. Unlike the earlier north/south divide, this trend is believed not to be related to environmental conditions but to existing culinary traditions, which were based on grinding grain and baking the flour in the west of the country, a technique that works well with wheat and barley. Traditions in the east, though, were based on boiling and steaming , which were much less well suited to these new cereals.
The study also found that wheat and barley were consumed in higher quantities by females at some sites in the Loess Plateau, suggesting that women may have been instrumental in pioneering the adoption of new culinary practices.