Stable isotope and dental-microwear analysis are methods commonly used to reconstruct dietary habits in modern and ancient human populations. However, it is rare that they are both used together in the same study, and here both methods are combined to obtain information on human dietary habits from the site of Tossal de les Basses (Alicante, Spain) through time. Middle Neolithic, Late Roman and Medieval (Islamic) individuals have been analyzed for carbon and nitrogen stable isotope ratios of bone collagen, as well as for buccal-dental microwear. Overall, δ13C and δ15N isotopic values show that for all periods the diet was mainly based on C3 terrestrial resources. However, the isotopic signature suggests a small, but clear amount of marine protein consumption during the Neolithic period and possibly also for a few individuals from the Medieval period. When compared to other studies from the region, it is also possible to see that the consumption of C4 resources was much more extensive during Medieval times than in previous periods. Microwear scratch density and length found for teeth from the Neolithic and Medieval periods reflect a diet in which tough foods predominated, requiring substantial pressure to chew in comparison with what was recorded for the Roman individuals. Combined with the δ15N data, the microwear signature suggests a higher input of marine/gritty resources among the Neolithic and Medieval populations compared to the Romans. Our findings also suggest that dietary patterns might be explained by cultural and technological population factors rather than habitat resource availability. ; Part of this research was part of DCSG's PhD, funded by the Max Planck Society (Prof. Hublin) and the Spanish Ministerio de Ciencia y Tecnología through a FPU predoctoral scholarship (ref. AP2005-1509). The development of this work was also supported by the BBVA Foundation (I Ayudas a Investigadores, Innovadores y Creadores), the Generalitat Valenciana (VALi+d APOSTD/2014/123), Aduna Proexa SL (Grant no. 1-06I), and the European Union (FP7/2007-2013-MSCA-COFUND, no. 245743 via a Braudel-IFER-FMSH in collaboration with the LAMPEA lab at the Université d'Aix-Marseille).