Proteins are essential biochemical compounds that are made up of polypeptides folded into shapes that facilitate biological functions. They help the body maintain health by keeping us alive and supporting a healthy lifestyle. The amount of protein needed depends on factors like age, size, and activity level, and nutritionists typically recommend multiplying body weight in kilograms by 0.8 or pounds by 0.37 to estimate daily requirements. Good sources of protein include meat, fish, eggs, beans, and nuts.