Of all the nutrients you need in order to achieve your fitness goals, protein is one of the most important. There are many foods high in protein – meats, eggs, and nuts are a few classic examples. But for people with ambitious fitness goals it’s difficult to take in enough protein from food sources alone. You can only eat so much meat or eggs in a day, meal after meal. Furthermore, if you restrain yourself to these food groups, you’ll probably end up struggling to find enough room in your stomach to absorb the desired amount of protein.