My idea is that "keto diet" is best. You'll find that doing "vegan keto" is a bit hard because plants don't have nutrients that are bio-available. "vegan keto" is insanely better than "vegan".

EG: "In the Nature study referenced by Dr. Patrick, the authors write, “…high intake of red meat relative to fruits and vegetables appears to associate with outgrowth of bacteria that might contribute to a more hostile gut environment,” and, “Together, our results suggest venues through which a diet low in fruits and vegetables relative to meats select for outgrowth of putrefactive bacteria, which might help promote colorectal carcinoma.”" from: https://medium.com/@pkslater/why-the-carnivore-diet-works-an...

Think of carnivore as a bonus, or an easier way to do keto (at least for me).

Feel free to ask on forums such as /r/zerocarb, /r/carnivore, etc for specific details including this one.

Also, carnivore is very-high-fat and low-to-medium protein. I literally buy 2.5kg fat-trimmings/week.