Hacker News new | ask | show | jobs
by camdykeman 4742 days ago
Yeah, I tried to edit the "completely" out of my phrasing almost immediately but comments had already been left so I couldn't.

To clarify, soy is a complete protein. What I meant was that the levels of BCAAs in soy are relatively low - especially when only taking in ~80g of total protein / day as the recipe suggests. This is why many longterm vegetarians/vegans often still have to supplement, dispite a high-soy diet. Soy protein is composed of about 18% BCAAs and is fast to metabolise, especially when isolated and diluted in liquid. Furthermore, without solid food in your stomach, certain enzymes are never released by your body's GI so metabolism is left almost entirely to your kidneys.
2 comments
axb 4742 days ago
I'm a long term vegan and I've never had to supplement. Plus 80g is on the high end, though obviously it depends on activity level.

The CDC recommends 56g daily for males 19 and up. Out of your daily calories somewhere between 10-35% should be from protein. http://www.cdc.gov/nutrition/everyone/basics/protein.html

That being said, you're correct that it isn't good to rely on one source of protein.

link
camdykeman 4742 days ago
It may vary with age.

I have two aunts and an uncle, all of whome were vegetarians for over 15 years and then were advised by their doctors to either supplement regularly or go back to eating some meat, simply due to protein deficiency and muscle attrophy, even though they're cyclists and hikers and just generally active people.

Personal circumstance definitely matters too. I work out regularly and over the past 6 years or so I've found recovery to be most difficult, long, and painful if I dont hit my goal of at least 1g of protein per lb of body weight, daily, from variable sources for continuous breakdown.

link
zachalexander 4742 days ago
So you said something that was completely wrong, and now you're backtracking in a way that also seems wrong.

Soy protein is 19% BCAAs, not very far from whey (the gold standard in protein quality IMHO) at 22%. And 85 g is significantly higher than nutritional bodies tend to recommend; the IOM recommends 0.8 g protein per kg bodyweight, for example, which works out to less than 85 g for most people.

If you work out, you probably want more than 0.8 g/kg, and probably more even than 85 g. I would actually agree with that, and plan to increase the brotein on the next mix I make. But this one was designed with ordinary people in mind, many of whom will find 85 g quite high.

link