“…The utilization of both 𝛿 13 C coll and 𝛿 13 C carb in isotopic studies, therefore, provides a more holistic estimate of several dietary inputs. In Europe, some studies have made use of both components (Dotsika et al, 2022 ; Etu‐Sihvola et al, 2022 ; Grupe et al, 2009 ; Gugora et al, 2022 ; Olsen et al, 2016 ; Reitsema et al, 2010 ; Toyne et al, 2022 ; Yoder, 2012 ; Zechini et al, 2021 ). Although 𝛿 13 C coll data from these studies suggested that dietary protein was primarily derived from C 3 resources, the differences in the 𝛿 13 C carb values among the individuals at certain sites indicated that some individuals may have consumed more C 4 or marine foods than others (Dotsika et al, 2022 ; Reitsema et al, 2010 ; Yoder, 2012 ), demonstrating the utility of analyzing 𝛿 13 C carb alongside 𝛿 13 C coll values.…”