Many green vegetables are actually great sources of complete proteins.
For example: Broccoli.. 1 cup of broccoli provides 3g of protein, and from a protein quality score (PQS) perspective it scores an 83, with large/balanced amounts for all the essential amino acids.
The average adult should consume between 0.8-1.8gm/kg. If you're mostly sedentary, then you need the low end, if you're an active athlete, you need on the high end.
So, for example, a 130lbs (59kg) woman who is a casual exerciser, might need 0.8g/kg. So she would need 47 gm of protein a day.
Now, 15 cups of broccoli might sound like a lot... but actually, if you consider all the other great sources of high protein greens out there, and then mix in other protein sources like nuts. You're not eating an unrealistic amount of vegetables to get to your protein needs just on vegetables.
Some other examples...
- 1 Cup of Kale - 2g... PQS 92!
- 1 Cup of Zucchini - 2g... PQS 89!
- 1 Cup of Sweet Potato - 4g!! PQS 82
- 1oz Cashews, Raw - 5g - PQS 100!!!! Wow!
- 1oz Macadamia Nuts - 2g - PQS 4 - Sad Face, but oh well. BUT -- complimentary with Mushrooms which give you 1g per "whole mushroom"