This study presents the results of a carbon and nitrogen stable isotope analysis of 39 human bone and 8 animal samples from Middle Bronze Age (or Middle Helladic, MH, ca. 2100-1700 BC) Lerna, Greece. The isotopic data indicate that the humans had a C-3 terrestrial diet while certain individuals appear to have significant amounts of animal protein in their diet. With regard to weaning age, the isotopic values and the estimated age of early enamel disruptions suggest that solid foods were starting to be used as a substitute for breast milk at or before the ages of 2.5 and 3 years old. (C) 2008 Elsevier Ltd. All rights reserved.