The human body processes different types of protein differently. For example, a protein shake will be digested differently from protein bars, and the absorption of proteins found in normal food will be slightly different yet.
A lot of people think this is because of the different physical forms of the protein. For example, they think that the absorption of proteins from solid food is different from the process of protein absorption based on liquid food products and digestibles. Furthermore, they assume that normal food is treated differently by the body than other protein bars and supplements in general.
These assumptions are partly correct. It takes, on average, about four hours for the human body to digest normal solid foods (and protein bars) and extract all the nutrients from them. On the other hand, the whey protein isolate found in most shakes can be absorbed by the muscles almost immediately, which makes them ideal for use after strength training workouts.
Protein bars are not nearly as effective for giving your muscles a growth burst right after working out, but they can still be highly useful to the aspiring or active athlete. You can throw some bars in your glove box so you’ll never be without a high-protein snack. You can slip some into your gym bag; they’ll do in a pinch in case you run out of time to eat beforehand, or if you forget your powdered shake supplement mix. You can even eat a protein bar with each meal to make sure you’re getting enough protein in your diet.
But as you do all of these things (or some of them), carefully monitor how much protein is in your diet to make sure you don’t get too much. It’s possible to cause irreparable harm to your kidneys and renal system if you get too much protein too often. It can also lead to kidney stones and the like.