A trainer was talking about this today, that there might be a valid reason for switching the type of protein you are taking, daily or weekly. Example: Taking Whey and switching to egg protein, didn't really dive into the conversation about this but wanted to get T-Nations take on this theory and why or why not it need to be done. I personally take whey protein daily and occasionally casein a couple times at night during the week.
I think Berardi did this- switched between Metabolic Drive or Grow! and muscle milk or something of the like.
Yeah I remember seeing Berardi recommend it too.
I guess it makes intuitive sense, just like eating nothing but chicken breast would seem like a bad idea. But If you're only using protein powder a little bit, and eating mostly real food (which you're hopefully varying), then I don't really see a point.
Thanks guys, I was not accounting for someone not getting a varied diet. I guess it does make sense to switch if you do not eat a variety of lean meats, vegetables along with your protein supplements.
Animal protein is complete protein. You don't have to change it.