More Than Enough for a Human Being, and Even More Than Enough for a Pig!
Here’s a rather dry and technical article that describes the amount of “available protein,” as opposed to “crude protein,” in the foods that wild mountain gorillas eat.
http://www.arts.mcgill.ca/anthro/chapman_files/cweb/Pdf/229_FiberNitrogen.pdf
The mountain gorillas in this study were getting more than enough protein, mainly because they were eating so many leaves. Although leaves are low in calories, a substantial proportion of those calories comes from protein. If gorillas eat enough leaves to get enough calories, the protein takes care of itself. A leafy diet is so rich in protein that the gorillas can afford to snack on some low-protein fruit.