Protein from Plants
According to Jack Norris, Registered Dietitian and the President and Executive Director of Vegan Outreach, protein is important for maintaining muscle and bone mass, for keeping the immune system strong, and to prevent fatigue.
People not familiar with vegan nutrition often assume it is terribly hard to get enough protein on a vegan diet, and that's if they even think there is any protein in plant foods at all (how they think vegans survive is an interesting question, though many of them probably don't think we do). On the other hand, once "educated", most vegans have the diametrically opposite view, considering it impossible for someone not to get enough protein on a vegan diet.
The truth lies somewhere in the middle. It is easy to get enough protein on a vegan diet if you eat multiple servings of high-lysine foods (legumes, seitan, amaranth, quinoa, pistachios, and pumpkin seeds) each day. But there are many vegans who are probably not eating enough high-lysine foods.
Legumes include soybeans and their products (tempeh, tofu, soy milk, soy meats, etc.), beans (garbanzo, kidney, pinto, etc.) and their products (falafel, hummus, refried, etc.), peas (green, split, black-eyed, etc.), lentils, and peanuts. Vegans who do not eat enough calories to maintain their weight also need to pay special attention to making sure they are getting enough protein.
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