With the broader aim of reconstructing long-term resource use and ecological history for better policy making in times of environmental change, this study is an attempt to decode the mutual effects of human subsistence practices, climate and socio-cultural organization in Sardinia between 4000 and 1900 BC. Was economy changing due to climate change? Was the environment changing due to economic practices? And how were economic practices and socio-cultural factors interacting? The answer is complex, and some convergence of complex systems theory, historical ecology and agency supports this. Diet, at the interface of all of these as fulfilling biological needs constrained by available resources, while being inextricably affected by ethnicity, age, class, gender roles, varies according to unceasingly changing variables.;Stable isotopic analyses of human bone tissues were used to build a quantitative dataset, and then integrate this with all the other proxies. The use of bone apatite besides collagen enhanced the dietary reconstruction and the contextual production of paleoclimatic data. The application of correction methods to ensure that dietary signature is distinguished from environmental noise enhanced inter-site comparability, making it possible to outline broad trends over time.;The results confirm the negligible role of seafood already documented in western Mediterranean late prehistoric groups. The long-held opinion that local Copper Age and especially Early Bronze Age societies relied more on herding than the Neolithic ones is not supported by the data: contribution of plant foods actually increased. Certainly the data do not indicate any heavier reliance on meat or milk and dairy. Considering the limited data from zooarchaology, material culture and landscape archaeology, the possible economic intensification could more likely be related to changes in power relations, gender roles and their construction through symbolically charged material culture. The two dry climatic events detected through delta18O values in accordance with previous independent studies seem to have had a role in triggering change, and such change followed specific routes based on the particular historical milieu.