  We present results for the ground-state mass shifts of octet baryons due to
the presence of a medium of pions or kaons from a lattice QCD calculation
performed at a single value of the quark mass, corresponding to a pion mass of
$m_\pi$ ~ 390 MeV, and a spatial volume V ~ (4fm)^3. We use a canonical
approach in which correlators are formed using a single baryon propagator and a
fixed number of meson propagators, up to n=9. From the ground-state energies we
calculate two- and three-body interaction parameters. We also extract
combinations of low-energy constants by comparing our results to tree level
chiral perturbation theory at non-zero isospin/kaon chemical potential.
