Protein is necessary for the proper growth, development, and repair of the human body.
Vegetarian foods can be a great source of protein, and contrary to popular belief, most plant-based sources of protein contain all the essential amino acids.
When quantities of particular amino acids, like methionine and lysine, are low, combining pulses with grains balances their amino acid content and makes them "complete".
For example, combining lentils with rice or hummus with wholewheat bread.
The current daily value (%DV) for protein is set at 50 grams per day and is meant as a general target for most people.
The average recommendation is 0.8g of protein per kilogram of body weight, and more (1-2g) if you are active.