Protein

Protein is a consumable item which can be purchased from shops of each region's League. It can be fed to a pokemon to increase the amount of attack that pokemon gains by 1 per protein per hatch. Each pokemon can consume a total of 5 proteins per unlocked region.

How to Use
Go to Start Menu > Items > Item Bag, select the protein and select a pokemon to use it on. Once used the effect stays permanently and does not get removed by any means.

New Efficiency
Below is a list of the most efficient pokemon to breed after they have been fed the max amount of proteins for that region unlock. Note that this does not take into account the reduced damage output for pokemon in non-native regions.