Food gained by fraud tastes sweet, but one ends up with a mouth full of gravel.
OJBLechem from sheker (deceit) is sweet to an ish, but afterwards his peh (mouth) shall be filled with gravel.
T4TPeople may think that food that they acquire by doing what is dishonest will taste very good, but later they will not enjoy what they have done any more than they would enjoy eating gravel/sand.