Soy vs whey

[Esseff]

I don't know if this has been discussed here before but the whey vs soy debate just rages on. Some say its bad for you due to the fact decreases testosterone levels, others rubbish that theory and say its fine.

Here two pro-soy articles: Whey vs. Soy -- You've Been Tricked and Soy Vs. Whey

For what its worth I eat about a kilo of chicken breasts daily, along with a post-workout whey shake so I'm not really pro-soy. Perhaps anyone here has some opinions to share...

[3speed]

I can't speak to the industry and regulatory climate in South Africa.  However, I can address the situation here in the USA.  Here, the supplement business is a $30 billion a year, largely unregulated industry that prays on the lazy and gullible.  I read both of the articles you referenced and there is only a debate because of people/entities with an agenda.

I'm not going to get into the soy/whey debate because, quite frankly, there isn't enough of a history of published studies concerning the two on which to base a concrete, valid discussion.  A lot of the available studies are contradictory and most of them were either poorly designed or designed with a bias.  (<--- I know-same thing)

The one thing that does have a multitude of good, quality studies is the amount of protein needed by the human body.  Study after study has come to the conclusion that, considering total caloric intake is adequate, a trained/training athlete needs 1.76 to 1.8 grams of protein per kilogram of bodyweight.  There are studies that break it down further to account for only lean body mass, but the above numbers still remain remarkably consistent.  That would put your protein needs at between 209 and 214 grams per day.  One kilo of chicken breast, on average, would contain 210 grams.  Undoubtably, you have other protein intake during the day as well so your shake is simply extra.  It won't cause any problems unless the calories are excess and being stored as fat and it, most likely, isn't providing any benefit other than convenient timing and there are more cost effective ways to accomplish that.