From what I read about protein supplements. If you are training hard and are finding it difficult to eat the additional cal and protein in to your normal 6meals during the day, then it might be useful...
However, if you are at your daily cal to maintain already, and you don't work them off, then it is still additional cal to become fat. And I'm not sure if it's a good idea to skip meals by eating the bars. I know the shake I had before would keep me full, but I will still eat my lunch.
Also, careful you don't eat too much protein as it could possible lead to kidney issues. I guess moderations is the key here.
http://www.TickerFactory.com/weight-loss/wFgBXFf/Pain is temporary. It may last a minute, or an hour, or a day, or a year, but eventually it will subside and something else will take its place. If I quit, however, it lasts forever. ~Lance Armstrong