This chapter principally concerns the interpretation of data collected via isotope ratio mass spectrometry (IRMS) and allied techniques in the context of food forensic applications. While isotopic composition data may complement other measurement results, the chapter addresses analysis and interpretation approaches that may be most informative with data consisting of isotope ratios. The chapter considers the importance of analytical accuracy and data quality in order to make conclusive inferences. It describes the common statistical approaches and methods for exploring food isotopic data. The chapter introduces two examples of investigating food authenticity and origin using statistical approaches common to ecological studies. It provides the reader with the necessary foundation and impetus to use data analysis and interpretation methods more effectively in addressing food forensic questions. The chapter introduces discrete and continuous approaches that are used frequently in the ecological literature for the determination of group membership and geographic origin studies.