Light clusters are included in the equation of state of nuclear matter within the relativistic mean field theory .
The effect of the cluster-meson coupling constants on the dissolution density is discussed .
Theoretical and experimental constraints are used to fix the cluster-meson couplings .
The relative light cluster fractions are calculated for asymmetric matter in chemical equilibrium at finite temperature .
It is found that above T = 5 MeV deuterons and tritons are the clusters in larger abundances .
The results do not depend strongly on the relativistic mean field interaction chosen .