Can you explain this? As I said recently, the whole GI thing is overplayed. Far more relevant is the Glycemic Load (GL) of each serving. The GL takes into account the GI as well as the amount of carbs per serving. The GL is the GI value multiplied by the actual number of carbs per serving. The carbs in a good MRP will typically provide a GL of around 1300, -roughly the equivalent to half a banana or less than half a cup of low GI brown rice!
Also, an insulin spike of not too excessive duration will decrease protein degradation and improve protein retention, i.e. improve anabolism.