One is nutrition less and hard to digest the other give you bitchtits and destroys muscle gains.
I would say soy. Increased estradiol receptor activation, increased oxidative stress from the rancid polyunsaturated fats in it, decreased gene expression involved in central and peripheral nervous system repair, etc. Soy is pretty much the worst thing you can eat.
Soy was not meant to be eaten. It does not want you to eat it. It makes proteins that mimic mammalian estrogens as a contraceptive to stop the population growth of mammals that feed on it. It is the same reason why the coffee bush produces caffeine and tobacco produces nicotine. The only difference is that caffeine and tobacco are made by plants to kill insects, whilst soy isoflavones are made to render sterile mammals who eat soy.
SUCKMYMUSCLE