Ok, you weren't being specific about those foods not containing much protein. Of course with most foods other than dairy and meat, there is generally going to be a higher ratio of fat and carbohydrates coming along with it.

I was trying to give examples of other foods containing protein to show that although meat is an excellent dense source of protein, there may be foods that also contain relatively high levels of protein that could also fit to serve other needs. I've been putting on a lot of new strength eating a can of salmon a day, with milk, and occasional eggs, as well as a large intake of fresh vegetables and fruits. I have a kidney stone requiring surgery, so I need to be careful about what I'm taking in.

Right now I'm doing research into the idea of eating a lot more leafy greens in my diet, they have very little in the way of calories, they're loaded with vitamins, antioxidants, and chlorophyl, and contain 4 grams of protein per serving. One serving seems like next to nothing when you eat it.

Gorillas apparently have the equivalent strength of being able to benchpress 4000 pounds, and this strength comes from the protein found in leaves. Their digestive system is very similar to our own.