This collection of seveteen papers, in French and English, forms the Acts of the XIVth UISPP Congress held at the University of Liege in 2001. The contributors discuss the role of the environment and the accessibility of resources on hunter-gatherer diet choices and changes through time. Reconstructions of palaeoecology, faunal species and human behavioural patterns are presented with case studies from Poland, France, Belgium, Croatia, Italy and Israel.