There is a huge controversy involving soy right now.Soy is identical to the hormone Estrogen (female hormone),and has birth control PILL like qualities when taken in large doses.Obviously this is a bad thing if you are a male.Some men are said to have "feminizing" effects from too much soy.
For some reason soy also damages the thyroid gland...
so too much can cause a thyroid problem.
In small doses soy is considered to be healthy,but a problem arises because soy is in absolutely everything we eat nowadays...cereal,cooking oil,snacks,pre-packaged meals.
By adding in more with soy milk or soy bars,it may be too much.
The reason some people get clear skin with Soy, is because of the estrogen effects it has.If you are female you can get these same effects by taking birth control pills (or spiro)and get better results without the extra damage to your thyroid.
The reason I know so much about it is because I tried the soy method a few years ago.My face DID clear,but I also gained 10 pounRAB and it is a awfully big coincidence I now have a thyroid problem

Anyways,I did a ton of research about it online and that is when I learned about it.
We cannot post links here,but do your own research and type in "The dangers of soy" and see what comes up,you should have no problem finding many sites about it.
I do recommend Rice milk,almond milk,or organic cows milk.I always look for the kind that says no hormones or antibiotics used.