The best vegetarian protein sourcesSpirulina and chlorella - Natural health researchers often consider these green algae to be the ultimate "superfoods," and for good reason: Aside from containing unsurpassed levels of chlorophyll and iron, spirulina and chlorella also contain 12 times more digestible protein than beef. Indeed, spirulina and chlorella are comprised of between 45-75 percent pure plant protein by mass. Consequently, spirulina and chlorella tablets and powders remain the protein source of choice for vegetarian and vegan body-builders seeking to improve muscle mass.
Sun-dried tomatoes - Second to spirulina and chlorella in the protein department are sun-dried tomatoes, which are tomatoes that have undergone an intensive moisture-removal process. Sun-dried tomatoes are extraordinarily rich in potassium, dietary fiber, vitamin K and a host of other nutrients. What really makes them stand out, however, is their whopping 11-16 percent protein content by mass - making them the most protein-rich fruits.
Beans - All beans are high in protein, though some are higher than others. Studies have shown that soybeans contain the largest amounts of protein (between 9 and 13 percent), followed closely by winged beans (9-12 percent). Lima, kidney, pinto, white and garbanzo beans are also good sources.
Buckwheat - Buckwheat is a gluten-free seed with a low glycemic index and more protein per 100 grams than corn, rice, millet or wheat. Furthermore, it possesses a unique amino acid profile; since buckwheat is high in arginine and lysine, it has the power to increase the protein value of cereal grains and beans consumed that same day.
Quinoa - Like buckwheat, quinoa is a gluten-free, low GI seed that contains almost as much protein as the best beans and legumes (often as high as 14 percent). It is also a good source of dietary fiber, phosphorous, iron and magnesium and makes a great substitute to rice or couscous.
Spinach - While spinach is famously high in iron, it also contains generous quantities of protein - sometimes up to 13 percent, although this figure varies wildly based on leaf quality. Spinach is extremely versatile (it can be added to pasta, salads, soups, casseroles and even pizzas), so there are many ways to disguise its unattractive taste.
Peas - Peas contains eight percent protein, making them one of the best common vegetable sources after spinach. Peas are also a good source of vitamin A and iron and are easy to incorporate into many meals.
Sweetcorn - Corn on the cob is high in protein and calories, making it a good food to eat before exercising. Just make sure you buy organic corn, especially in the United States.
Brussels sprouts - Sprouts are rich in protein and vitamin C and are a good weight loss food due to their low calorie and fat levels.