Purpose: Based on avaliable literature the objective of this study was to determine if increased protein intake is beneficial in terms of muscle growth for people on a normal diet and with low or high physical activity. Methods: Information was obtained by searching and reading articles concerning this topic. By studying and evaluating the different articles, it was possible to absorb sufficient knowledge to answer our main question. Results: A higher protein intake than what is recommended, 0,8 g per kg bodyweight per day, will not increase the muscle growth of sedentary people. This is also seen for people who are physical active despite that it is expected that they require more protein than people with low physical activity for optimal muscle growth. Possible reasons for these are many. Firstly amino acids are quite efficiently recycled in the body, implying that the required intake of amino acids in general is low. Moreover, increased requirement for energy such as carbohydrates and fats when physical active will through interconvertion cover most of the need for non-essential amino acids required for muscle growth. The only source of amino acids that may need to be increased during exercise is essential amino acids. However, an average Norwegian diet contains more than 1,2 g protein per kg bodyweight and contains ample amounts of all amino acids, including essential amino acids. This suggests that a normal diet in it self will be sufficient to support the protein requirements for muscle growth of most people, also physical active persons. Finally, it should not be excluded that timing of food/nutrition intake may be of importance for optimal integration of digested amino acids into muscle protein. The latter may not be a problem since food variety and availability is generally good.Conclusions: Taken together physical active people, will in general get sufficient protein in their normal diet implying that additional protein supplement is not necessary. The only exception may be that highly physical active persons may require additional amounts of essential amino acids for effective muscle growth. Finally, the timing of the protein intake may also be important.