  Continuum SED models of gamma-ray burst (GRB) and obscured GRB host galaxies
at moderately high redshifts are presented and compared with those of
superluminous supernovae (SLSN), starburst (SB) and active galactic nuclei
(AGN). We consider that continuum radiation (bremsstrahlung) is emitted from
the same clouds which emit the line spectrum in each object. Therefore, we have
selected from the samples of the GRB host continuum observations those that
were previously modelled on the basis of the line spectra, because modelling
the continuum SED is less constraining. The bremsstrahlung is generally
recognised in the radio and in the UV-X-ray frequency ranges, while dust
reradiation peaks in the IR. To reproduce the continuum SED of most of the GRB,
SLSN, SB and AGN in the near-IR-optical range, the contribution of an old star
background population is needed. This radiation can be reproduced by a black
body (bb) corresponding to temperatures T_{bb} =3000-8000 K. The best fit of a
few host SEDs includes also the direct contribution of the bb flux from the SB
corresponding to Ts about 5 10^4K. d/g calculated by modelling the SEDs of
obscured GRB hosts roughly increases with z resembling the SFR trend.
