Stable isotopes reveal dietary shifts associated with social change in Hellenistic, Roman and Late Antique Knossos

•Diet at ancient Knossos, Crete, in Greece changed in line with major social changes.•Stable isotope analysis of human remains highlights dietary changes.•Most people at Knossos were eating some meat or other animal products.•Females had wider ranging isotopic values than males.•Fish or seafood consumption increased in Late Antiquity.