soy v. whey?

[Cradler]

A friend of mine showed me an article recently debating the merits of soy protein isolate v. whey protein (they discuss both concentrate + isolate). Some of the discussion was a little over my head - particularly in passages relating to estrogen receptors - such that while it sounded good, I had no way of verifying its accuracy. And some of it clashed with what I thought I already knew, particularly: "For years, bodybuilding gurus have recommended the use of soy protein for pre-contest bodybuilders who need to shed body fat while keeping as much lean muscle as possible." (IK/other competitive BB'ers on here, is this true? I had always thought soy would cause perhaps more bloating than would be desired pre-comp.)

So I looked at a few more articles (knowing that I don't really know much about the sources, but nevertheless) and it seems to say simply that soy is nutritionally better than or equal to whey (certainly better according to the first article) but that whey is preferred for its fast absorption rate.

Primarily, I was curious if that was an accurate (if crude) summary of the distinction between the two, or if the case for soy is being overstated. Second - if it is true, and whey's most useful application is for quick absorption, would it be best to use soy as one's primary source of protein and only use whey for pre/post workout?

Thanks in advance for any replies!

[Eric3237]

I've seen the first article before and the site. If you look at the rest of the content you'll see that it's basically promoting a vegetarian lifestyle for lifters. I've done that, btw, and it ain't easy....a bodybuilding diet is hard enough to maintain without the restrictions...so you'll find that a favorite gambit is to try to convince you that you don't need so much food and protein, etc...and that of course you can get enough protein from vegetarian sources. Well you can but you will find it tortuous unless you believe you hardly need more than a regular person at a smaller size to you to boot.

So there is an agenda there. Pretty much right off the bat if you see someone promoting one protein source as superior over another you have to call it into question. Because, quite frankly most of the common protein sources are very good protein sources

The second article you listed is a better account of it I think. I didn't look at the third yet.

I've done a lot of research on all this but even without that I can give you a quick opinion. And that is because your question is based on extremes. I.E. only use whey for this and use soy all other supplementation. You can pretty much rest assured that the middleground is the better option in these matters.

So if you are interested in using soy, and I would recommend an isolate, then use some as well as whey. I would definitely stick to whey as the pre/post workout protein but other than that experiment and see how the soy sits with you. It can be a little bit tougher to digest but an isolate helps. No, I don't think it's going to "feminize" you or anything of the sort.

The only soy product that I have had problems with in the past in terms of digestion I associtated with soy milk in too large amounts. But there were also other sources of soy in my diet. These included products like tofu, tempeh, and products derived from soy flour and soy concentrate. So you can see it was a mixed bag and yes, I've had some problems with too much. I used a few tubs of soy isolate in the past and found it quite satisfactory. But I've personally never use what I would call huge amounts of the isolates for very long periods so I really can't help you predict the outcome of that. But you can have too much of anything. Including whey...although I generally can tolerate large amounts of that.

Best I can say is not to get too caught up in any one thing. I sure love my whey to help top off my protein needs but I wouldn't have a problem including a soy isolate. To be honest I don't know why I don't...it would probably save money.

I've never tried to get down to super-dry status so I can't say much about the bloating issue. I've never looked at myself and said "i'm bloated". Especially since I don't have no monthly cycles

[IronKitten]

Originally Posted by Cradler

(IK/other competitive BB'ers on here, is this true? I had always thought soy would cause perhaps more bloating than would be desired pre-comp.)

I've honestly never heard any competitors saying that they'd NEVER use soy protein during a prep. But most commonly, people in comp prep will stick with primarily whey isolate. And generally, people in prep don't use protein supps as much since A) we'd rather have real food most of the time since our portions get smaller and smaller and B) most people cut out all protein supps at some point during prep, so it's best not to get used to having shakes all the time.

Now, the issue of bloating due to protein supps... Some people cut it out during their whole prep, some cut it out during the last month, some only cut it the last week, and there are others that never cut it. But really, the amount of water that PP would make you hold is a pretty small amount (well, with whey at least).

I've never been one to use soy products much at all, so as far as the differences between the two, especially in terms of contest prep, I can't really say.

[Cradler]

Originally Posted by Eric3237

So there is an agenda there. Pretty much right off the bat if you see someone promoting one protein source as superior over another you have to call it into question. Because, quite frankly most of the common protein sources are very good protein sources

I feel stupid not having gone back to the source site. Thanks for pointing this out.

So if you are interested in using soy, and I would recommend an isolate, then use some as well as whey. I would definitely stick to whey as the pre/post workout protein but other than that experiment and see how the soy sits with you. It can be a little bit tougher to digest but an isolate helps.

Makes sense. I didn't mean to suggest that I wanted to go all one way or the other - it was really just that it seemed to be painted as such a black/white issue of their relative merits. If it was the sort of thing where one had some strict advantage over the other then I'd be more interested in trying it, but if it's mostly a matter of preference - which it sounds like it is - then I probably won't worry about it... although, now I think on it, next year at college it might be handy to know a few good ways to save money...

No, I don't think it's going to "feminize" you or anything of the sort.

Haha, I wasn't too worried about this part

*

@IK: Thanks for the response. I'm not planning on competing any time soon - cutting weight for one season out of the year is enough for me but nevertheless that's helpful, so thank you.

[Eric3237]

Wow, we maybe can scratch that idea about soy isolate being cheap. I just looked at scifit becasue they tend to be an inexpensive brand. About 30 bucks for 2.5 pounds. That's certainly no cheaper than a good whey.

[Ross86]

14.99 for ON's 2lb Soy Isolate at NP

[Eric3237]

That's weird.