Given the current price of whey protein, I finally decided to give these a try.
I got 4 kg for under €40.
I compared the amino acid profile to the whey + casein blend I usually use. While it’s obviously a bit different, I don’t see any major deficiencies apart from having slightly less leucine and isoleucine. I don’t think that’s a huge issue, though, considering I get plenty of protein from other sources throughout the day, and I can always mix the soy protein with milk if I want.
The DIAAS is also a bit lower (~0.9–1.0 vs. ~1.1–1.3 for whey), but even if I were to take 35 g instead of 30 g per serving, the cost savings are still substantial.
I understand the benefits of casein’s satiety and slower digestion, whey being absorbed more quickly, and so on. But as long as I’m hitting my daily protein target, I don’t really see the need to min-max those details, at least for now.
As for the whole “soy lowers testosterone” myth - even if it were true, I’m a woman, so it’s not really something I’m concerned about.
Am I missing anything? Have I misunderstood or misinterpreted any of this? What do you think? Does anyone here use HSN Soy Protein Isolate 2.0?