After reading an article on T-nation last night I came across an interesting paragraph: Whey is absorbed very rapidly (and therefore poorly), and contains amino acids that are quickly converted to glucose upon ingestion. This spikes your blood sugar, which is not what you want if you're trying to get over insulin sensitivity. Link to the full article: http://www.t-nation.com/article/most..._created_equal In response to this I posted a link to the article on the Precision Nutrition forums and this was Dr. Berardi's response: "All foods cause an insulin spike...and in some cases, even smelling a food causes an insulin spike. However, the magnitude of the spike is what's important. Now, I don't have the data on hand as to how much insulin is released but I'm guessing it's not the same magnitude as eating a big carby meal. However, let us know what you find. Further, in this article, the author is saying just taking whey alone in water causes this. If you're following PN, it's unlikely that you're doing this." _______________________________________________________________________________ I searched for some other studies but could not find anything testing blood sugar before and after consuming whey alone, however I learned that consuming whey protein (and other milk proteins) with a carb source increases the insulin response greater than consuming the indentical carb meal with a non milk source of protein. http://www.medscape.com/viewarticle/494021 * Milk components affecting the glucose and insulin responses include carbohydrates and proteins. Milk carbohydrates have low GI, while the milk proteins casein and whey may have insulinogenic properties by activating the incretin system. * Milk proteins contained in the whey component (resulting in release of the amino acids leucine, valine, isoleucine, and lysine) may be primarily responsible for the insulinogenic properties of milk products. __________________________________________________________________________________ Just some information that could prove useful, and for anyone concerned about insulin sensitivity or people OCD about their diet like me.