“Sources of Plant Protein Grains and grain products, legumes (lentils and dried beans and peas such as kidney beans or chickpeas), starchy vegetables, and nuts and seeds all provide protein (see Table B). A serving of a grain product or starchy vegetable provides an average of about 5 grams of protein, a serving of legumes provides 10 to 20 grams of protein, and a serving of vegetables provides about 3 grams of protein. Although a serving of these foods contains less protein than a serving of meat, you can eat more plant protein foods for fewer calories.”
Book:Nutrition