Phinney and Volck talk about lean meats and hunter/gatherers. They fed the lean stuff to their dogs and mixed kept the fatty stuff for themselves. You can actually preserve things in fat, which they did. Making pemmican and such. There was quite the trade in Olichan fat, from a very fatty fish. They talked about the "Grease Trail" which was a trading route the native Americans had to get the great fat the coastal folks had.