The distribution of stable isotopes and certain elements within a food web make it possible to draw direct inferences regarding diet, trophic level, and subsistence.

Isotope analysis is a completely different technique from radiocarbon dating, which is used to measure the age of organic materials.

Bone recovered from archaeological sites can be analysed isotopically for information regarding diet and migration. Carbon and nitrogen isotopic signatures are used to reconstruct diet, and oxygen isotopes are used to determine geographic location.

To obtain an accurate picture of palaeodiets, it is important to understand processes of diagenesis that may affect the original isotopic signal.