I use to drink one quart of soy milk a day. Thought I was doing great. Getting all my good proteins.
Some time later I went to a natural health doctor complaining of no energy.
Her first question - Do you consume any soy products?
She informed me that soy contains a specific acid which blocks the absorption of minerals in the intestines, and that the body will only absorb nutrients to the degree that minerals are present.
She told me that my body was starved. -- I totally agreed!
Within two days I noticed a big improvement from eliminating the soy.