Made from wheat gluten, seitan is full of protein. It offers a lot of nutritional value but should be avoided by anyone with gluten or wheat allergies or celiac disease. According to this article in verywellfit.com Seitan is almost pure protein. Therefore, it serves as a great source of protein for people following vegetarian and vegan diets, who sometimes struggle to get their daily allotment of protein. Just one serving of seitan (around 2.5 ounces) contains around 17g of protein. Although seitan is a processed food, it can represent a healthy addition to your diet as a protein-rich meat substitute that is low in saturated fat. Since it can take on the taste of meat (depending on preparation), seitan-based dishes and meals might appeal even to some confirmed meat-eaters, perhaps aiding in a switch to a more plant-based diet.