Diet in the Middle Ages is known through different complementary sources: cook books, animal bone and plant remains, as well as human skeletal remains discovered in archaeological sites. This paper focuses on the analysis of human skeletal remains. The aim was to define dietary patterns and the state of health at the end of the Middle Ages. This analysis is based on two sets of dietary indicators: osteological (tooth wear, caries, alveolar lesions) and isotopic (stable isotope of carbon and nitrogen). These dietary indicators were analysed for the French Medieval Saint-Laurent population of Grenoble (Isère), which dates from the 13^th to the 15^th centuries AD. Osteological indicators show a dietary behaviour shift corresponding to a decrease in vegetable consumption associated with an increase in the consumption of cariogenic and pastry food and/or more cooked meals between the 13^th and 15^th centuries AD. Isotopic indicators demonstrate an increasing consumption of animal proteins between the 13^th and 15^th centuries. These results seem to fit with the environmental and historical contexts. The dietary shift revealed by osteological and isotopic indicators could have linked with improving living conditions in the 15^th century. This change could have been due to either specific political laws regulating the allocation of food or the high social status of the individuals buried in the cloister of the church in the 15^th century.