We have been brainwashed into thinking that we need a lot of protein, up to 30% of our total caloric intake. While this might work for short-term weight loss, it can often lead to health problems, especially if you have a high intake of animal protein. Not only do we not need a lot of protein, there are many non-animal based sources that we can get it.
How Much?
The World Health Organization suggests we get a minimum of 35 grams of protein daily. Furthermore, a study of the healthiest people on earth (those populations with the highest percent of people living to be over 100 years old) found that they do not eat more than 50 grams daily. Unfortunately, the average American gets a whopping 150 grams of protein a day, which is a lot more than the body is built to digest. You are better off eating less animal-based protein, though if you do, do not eat so much.
Protein from Nuts and Seeds
Nuts and seeds are mostly composed of fat and protein. They are also a good source for EFA (essential fatty acids) and vital minerals like calcium and magnesium. Flaxseed, walnuts, pumpkin seeds, and almonds are all fairly good sources of protein. For example, an once and a half of pumpkin seeds (about 250 cals) has 13 grams of protein.
Protein from Vegetables
Although you would have to eat a whole lot of vegetables to get a lot of protein, these proteins are very good for the body and easily broken down. For some figures, 1 cup of raw watercress has 1 gram of protein. It also has 4 calories, so a salad with a watercress base may be a good source of vegetable protein. Soybeans, potatoes and mushrooms are other vegetable sources of protein that don't requires quite as much quantity for the same amount of protein.
There are also several "superfoods" which are very high in protein. These include spirulina, chorella, cacao beans, hemp seeds, maca root, mesquite root, and goji berries. These foods have other very nutritious properties and should definitely be a part of any diet.
The key is not to be tricked into thinking you need a lot of protein when you don't. The truth is that the human body is well adapted to eating little meat, and also preserving the protein and muscle that we have even when we aren't accumulating more.