  We discuss the influence of momentum-dependent correlations on the
superconducting gap structure in iron-based superconductors. Within the weak
coupling approach including self-energy effects at the one-loop
spin-fluctuation level, we construct a dimensionless pairing strength
functional which includes the effects of quasiparticle renormalization. The
stationary solution of this equation determines the gap function at $T_c$. The
resulting equations represent the simplest generalization of spin fluctuation
pairing theory to include the effects of an anisotropic quasiparticle weight.
We obtain good agreement with experimentally observed anisotropic gap
structures in LiFeAs, indicating that the inclusion of quasiparticle
renormalization effects in the existing weak-coupling theories can account for
the observed anomalies in the gap structure of Fe-based superconductors.
