The amount of protein needed by the human body per day varies depending on several factors such as age, sex, weight, and level of physical activity. Generally, the recommended daily intake of protein for adults is 0.8 grams per kilogram of body weight. However, athletes and individuals who engage in regular intense physical activity may need more protein to support muscle growth and repair. It is important to note that excessive protein intake can also have negative effects on the body, so it is essential to consult with a healthcare professional to determine the appropriate amount of protein for your individual needs.