We compare the structures of the theory of causal fermion systems (CFS), an
approach to unify quantum theory with general relativity (GR), with those of
modified measure theories (MMT), which are a set of modified gravity theories.
Classical spacetimes with MMT can be obtained as the continuum limit
of a CFS. This suggests that MMT could serve as effective descriptions of
modifications to GR implied by CFS. The goal is to lay the foundation for
future research on exploring which MMTs are consistent with the causal action
principle of CFS.