  We present lower bounds for the coefficients of Ehrhart polynomials of convex
lattice polytopes in terms of their volume. Concerning the coefficients of the
Ehrhart series of a lattice polytope we show that Hibi's lower bound is not
true for lattice polytopes without interior lattice points. The counterexample
is based on a formula of the Ehrhart series of the join of two lattice
polytope. We also present a formula for calculating the Ehrhart series of
integral dilates of a polytope.
