Form and type of protein?

In the podcast episode "Dr Layne Norton: The Science of Eating for Health, Fat Loss & Lean Muscle," various forms and types of protein are discussed, particularly focusing on vegan options. Layne Norton explains that soy is a complete protein source, meaning it contains all essential amino acids necessary for human nutrition. Additionally, soy protein does not negatively affect testosterone or estrogen levels when consumed in moderate amounts. Another interesting option mentioned is potato protein isolate, which has a similar amino acid content to whey protein but is less commonly found.

For vegans, a significant development is the creation of whey protein from non-animal sources, such as yeast, which provides a high-quality protein option for those avoiding animal products. The bioavailability of isolated proteins (like the mentioned potato protein isolate) is generally higher than that of proteins bound up in plant material, although cooking can help increase this bioavailability. However, it is noted that plant-based proteins tend to have lower plasma amino acid levels compared to whey, even though they can stimulate protein synthesis effectively when consumed in adequate amounts. The discussion also highlights the importance of leucine, an essential amino acid, in stimulating muscle protein synthesis, noting that animal-based proteins like whey and egg have higher impacts in this area compared to plant-based sources like wheat and soy when consumed at typical dietary levels 1.