Soy protein isolate is a highly refined plant protein derived from soybeans. Since it’s an isolated form of protein, soy protein isolate products are at least 90% protein by weight1 and nearly carbohydrate and fat-free.
Like other types of protein isolate, soy protein isolate is produced by separating the fiber2, carbohydrates, fats, and other nutrients from concentrated soy protein. While this creates a highly concentrated form of soy protein, it’s more processed than soy protein concentrate and significantly more processed than soy products like tofu, tempeh, and edamame.
“Soy protein isolate has a high nutritional value as it contains all nine essential amino acids required for human health. It’s also low in fat and carbohydrates, making it an attractive option for people looking to increase their protein intake while minimizing calorie consumption,” explains Kien Vuu, M.D., a human longevity and performance expert and assistant clinical professor of medicine at UCLA.
“Soy protein isolate is typically used in dietary protein supplements (e.g., protein powders, bars, shakes), meat alternatives, food fortification, and as emulsifiers or thickeners,” Vuu adds.