I've been eating beef tallow past three weeks. Not strictly carnivore, but using the broth and oil from my cooking pots. Wow I feel great. The best part is that the beef tallow is free. I went to the butcher and asked for some fat trimmings, they laughed and asked me what for. To render tallow. I got a 5lb bag for free.

Also I discovered I can use Rosemary in the fat, for flavor and memory improvement.