Clen is anti catabolic, clen is not pro anabolic.
Going 1k cals in to deficit AND adding clen is probably not the best of ideas. The only way i would do that is if i were pinning AAS. And even then i wouldn't go 1k in to deficit.
OP, what is the reason you need to go in to such a steep deficit? Maybe we can toss around a few other (better) ideas.