People have been led to believe that protein is such an essential nutrient that one must actively pursue foods that contain high amounts of it, even when those foods, such as meat and dairy, compromise our health in so many ways. We have also been led to believe that only animal-based foods contain sufficient protein and, furthermore, that we need to eat those foods to avoid becoming protein deficient. The reality is that protein deficiency is almost exclusively seen in people suffering from a calorie deficiency. In these cases, there will be an overall nutrient deficiency, not just protein deficiency, and when this happens the concern should be getting more calories and all nutrients, and not just more protein.
As for how much protein a person needs, the answer is the amount that a diet of whole, plant-based foods provides. All whole, plant-based foods have protein. People thrive on a plant-based diet without ever going out of their way to find sources of protein. Indeed, we’ve evolved over millions of years without ever aiming for a “source” of this or any other nutrient.
With a diet based on fruit, vegetables, tubers, whole grains, and legumes, about 10% of your total calorie intake will be from protein. However, you should not concern yourself about how much protein you’re getting any more than you should worry about the perfect number of breaths you should take in a day. If you’re worried that 10% isn’t adequate, note that there’s evidence that consuming too much protein is harmful—especially when it comes from animal sources.