When many people thing "protein," they think of meat. However, Harvard nutritionist Walter Willett points out that legumes and nuts, as well as many other vegetables, deliver a high amount of protein by volume. In some cases, this content is higher even than roast beef or steak. Willett writes that, unlike the protein in meat, proteins in plants are not complete proteins, so you must eat them in combinations to get the benefits you would out of eating meat. This "protein mixing" doesn't have to happen in the same meal, or even the same day.
Broccoli's dry matter consists of 33.6 percent protein, according to information posted at DietaryFiberFood.com. Compared even to beef, at 34.34 percent, that's a lot of protein for a vegetable. Broccoli's cousin cauliflower, weighs in at 27.34 percent protein.
Peas and Beans
Peas, beans and other pod plants carry a healthy dose of protein. Peas consist of 27.34 percent protein, with peanuts rating even higher at 29.57 percent. Green beans deliver 18.1 percent of their mass as protein.
Fruits, as a whole, carry less protein than beans and green veggies, but some do contain moderate amounts. Cantaloupe scores the highest at 11.24 percent, with strawberries and oranges, bananas and watermelon all delivering more than five but less than 10 percent by dry volume.
According to Willett and Dr. Steven Pratt of "Superfoods Rx," soy is the only vegetable that delivers a complete protein on its own. How much protein soy delivers varies by method of preparation. Edamame--soy beans still in the shell--carries 18 percent protein, while firm tofu provides 14 percent. Other variations of soy include natto and soy-based alternatives to meat and dairy products.
Soy is not the only bean rich in protein. Black and navy beans are both 7.5 percent protein; and pintos and lentils, 10.5 percent. Other high-protein beans include white, red, garbanzo and lima. Blackeyed peas are an exception, delivering only three grams of protein.
Nuts carry much of their dry weight in protein. According to nutrition website "The Calorie Counter," cashews are over 18 percent protein. Almonds and peanuts are 25 percent protein, pecans 9.6 percent. Other high-protein nuts include walnuts, pine nuts and acorns.
Other High-Protein Veggies
Asparagus is the highest rated vegetable at 36 percent protein by dry weight. Celery, often considered bare of anything except crunch and aroma, carries 11 percent protein. Avocados also come with a high protein content--almost 11 percent.