when off, despite the low presence of adrogens in the cycle, estrogen becomes a problem off cycle for about 4 weeks.
a little fat starts accumulating subcutaneosly, and the diet really has to be watched during that time.
since estrogen if the primary culprit in body fat accumulation the nolvadex is used to compete with the estrogen in the body till natural test production comes back.
even Charles Glass in a recent MM INTERNATIONAL article stated that nolva ahould be used post cycle for those very reasons.
personally I don't believe in clomid I think it only temporarily raises your testosterone, and then you crash again.