If you prefer to avoid eating meat or animal products, you can get your protein from other sources. Lentils, beans, chickpeas, nut butter, oats, soy, quinoa, and Ezekiel bread, are some of your options. However, there are three non-meat protein sources which most vegans and vegetarians consume: tofu, tempeh, and seitan. These foods are not very common in an omnivore's diet. People who enjoy the taste and texture of meat do not substitute it.
Tofu and tempeh come from soybeans, while seitan from the protein in wheat (gluten). The following slides will describe each food in detail, including its potential benefits, nutrition value, and downsides.
Tofu is vegan cheese made from soy milk. The recipe is Chinese, but nowadays, most of the soybeans come from the USA. If you want to stay away from GMO foods, check the labels before buying tofu (organic, non-GMO brands are the best).
Nutrition-wise tofu is surprising. It contains all the essential amino acids, plenty of minerals, and has a low amount of calories.  There are many kinds of tofu, but most of them are rich in protein and calcium. Tofu also contains isoflavones. Their potential health benefits are related to illnesses that come with age. Soy isoflavones can prevent cardiovascular, brain, certain cancers, and bone issues. 
The downside of tofu is the presence of antinutrients. It has trypsin inhibitors, which do not allow the proper digestion of protein, and phytates, which interfere with the absorption of calcium, iron, and zinc. However, they are not something worrisome as long are you are following a balanced diet. Besides, you shouldn't consume soy products in high quantities due to their estrogen content. Studies didn't manage to find a link between breast cancer and soy products, but it doesn't mean it has to be the primary food in your diet.
Tempeh, an Indonesian food made from fermented soybeans, is a popular choice among vegans and vegetarians. It contains plenty of nutrients, and there are so many different ways to cook it. Tempeh has a chewy texture and a nutty flavor. The protein content of tempeh is higher than that of tofu. It is also a good source of minerals (calcium, magnesium, potassium, and zinc) and vitamins. 
Similar to tofu, it can prevent cardiovascular, brain, certain cancers, and bone issues, due to its content of soy isoflavones. The main difference between the two soy-based products is the fact that tempeh is made from fermented soybeans, hence the presence of prebiotics. Prebiotics aid the digestive system by helping with nutrient absorption, breaking down food, and reduce IBS symptoms. 
The only downside of the non-meat protein source is that it contains soy, which is a goitrogen. This substance might interfere with thyroid function. 
Moreover, if you have a soy allergy, you should avoid it altogether. You can use tempeh in salads, stir-fries, burgers, main dishes, and more!
Seitan is made from hydrated gluten. You can buy it from the grocery store, or you can make it at home by mixing purified dried gluten powder with water. Seitan doesn't have a strong taste, and it doesn't interfere with the flavor of seasonings or sauces. It is a very flexible ingredient, and you can easily incorporate it into any meal.
Seitan has plenty of protein. Vital wheat gluten contains 75.2g of protein per 100g. A serving of seitan contains 28g of gluten, which is the equivalent of 21g of protein. It's a good option for vegetarians who have soy allergies.
The downsides of seitan, however, outweigh those of tofu and tempeh. Seitan is a highly processed food; it doesn't exist in a natural state. Nonetheless, when you consume a diet rich in healthy foods, adding seitan in moderation isn't a matter of concern.
People who have celiac disease, gluten-intolerance, or other similar issues, cannot consume it. Also, some of the pre-packaged items can have high quantities of sodium.
A diet rich in gluten can lead to intestinal permeability, which promotes food sensitivities and auto-immune diseases. 
on February 14, 2020