Well, they are obviously not the same but the motivation behind both is the same for most people. People are in search of gaining control over their health and seek it in absolutes and ideals. The pursuit for perfection and imposing ideals over nature which is what this is, has in the past lead to disastrous outcomes. It is a slow process, you start looking for perfection and those high ideals (read idols) make you want to make your diet perfect, understandable, clean in a way that is not reflective of reality, history, or science.
A few weeks ago, I attended Keto Con, it wasn’t a surprise, I encountered several people who when I asked them about whether they are on a ketogenic diet, said something like “yes, for x amount of time, my goal though is to be full carnivore.” You used to hear the same thing in the vegan movement but with the goal of being raw vegan.
Especially beware of the 20-somethings who espouse these diets. At that age, with enough activity, you can look pretty damn sexy no matter what you are eating and in our age of instagram, it can be very seductive for a lot of people, even older, just looking for something easy to understand hyped with sex appeal. I’ve been watching these movements for over 20 years. While there are some original influencers that still look great, the majority well . . . . enough said. Of course, that might have absolutely nothing to do with the diet as we’ve discussed prior. Can you do either of these in a healthy way? Yes, perhaps, but that doesn’t mean you should.