The Upper Seine Valley sees during the Bronze Age an increase in settlements and cemeteries characterized by a variety of architectures and funerary practices. This variability originates from the coalescence of two cultural traditions, the Atlantic culture from the northwest and the Continental culture from the east, which find its roots in the Upper Rhine area. In this context, our research aims to understand the cultural identity of these communities by reconstructing subsistence economy and palaeodietary patterns and to trace human mobility, which influenced lifestyle and social–economic dynamics. Adding new 10 AMS dating and using multi-isotope (δ 13 C, δ 15 N, δ 34 S) and multi-proxy (botanical, animal and human remains) biochemical investigations, we detected changes in dietary habits throughout the Bronze Age linked to varying C 3 and C 4 plant consumption and diverse animal protein intake by humans. Three main outcomes are highlighted: (1) a variety of farming strategies with different manuring intensity according to the cereal species; (2) site-specific dietary patterns; (3) an increase in millet and animal protein intake during the Late Bronze Age. Moreover, results from one cemetery reveal that individual mobility is more significant for males. These dietary variations, differential agricultural strategies and mobility are consistent with other western Europe research, supporting major global changes in all of Europe at the end of the Bronze Age.