I followed a grain free diet for over a year and I know think it's incomplete. The trouble with the high protien from animal sources diet is the acidifying effect on the body. As we now know all dis-ease states are acidic and rebalancing your internal ecology to one of a more alkaline nature brings you closer to health. Also lots of protien puts strain on the liver over time. Personally, I now follow the BED diet and make sure my grain consumption is only 20% of any meal. I make sure the grains I eat are well soaked. I always eat them with lacto-fermented veggies and I've included sea veg into my diet.
Grains were traditionally never "conveinient". They were treated with respect and prepared well;-) They've become junk food because of our insistance of speeding everything up and slaping them into dishes too quickly.