There is no doubt that your body needs protein. Day after day your body uses it to build muscles, skin, blood and more; it is a component of every cell and vital for healthy functioning. Without enough protein, you might find yourself becoming easily fatigued or even lethargic, experience edema (fluid retention), lose muscle mass, become constipated and have difficulty healing from wounds or injuries. Although true protein deficiency is rare in developed nations, it can occur in people following crash or fad diets, those with eating disorders or elderly/invalid people who have difficulty getting enough nourishment.
In Western countries, the issue for most people isn't how much protein they are getting but from what sources. A person who eats a lot of steaks, burgers and deli meat is consuming more than enough protein but is also consuming an excess of saturated fat and sodium. Many people are concerned that vegetarian and vegan diets are too low in protein however plant sources of protein such as beans can provide ample amounts as well as other nutrients such as vitamins and fiber.
