Paired analysis of femoral and rib bone collagen from 12 individuals at the Selivanovsky II burial ground reveals variable isotopic shifts in δ15N values between childhood and adulthood, reflecting differences in dietary protein intake across individuals.

When babies stop breastfeeding and start eating solid food, their bodies begin using protein from meat or dairy instead of milk. This changes the type of nitrogen found in their bones. Bones that grow slowly, like the thigh bone, keep a record of the diet from early childhood, while bones that renew quickly, like the rib, show what was eaten more recently. The difference between these bones shows how each person’s diet changed as they grew up.