When I searched about people who support this diet I found two interesting things. For one, these people (as seen in this [3] reddit thread) are convinced that modern society likes the taste of carbs and feel "safe" eating plants, so people don't want to spend money on researching keto diet (as seen in that thread). I'm skeptical of this since research institutes do research on things public is not generally interested in.

Second, proponents of this diet seem to think this diet is practiced by ancient humans before agriculture. Recall the contents of Iceman Otzi's stomach before he was murdered [4]: fatty goat meat and pure fat (lard). We, HN, recently discussed the lifespan and general health of our ancestors. [5]

There is also this [6] research paper:

> A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates.

[1]: https://www.ncbi.nlm.nih.gov/pubmed/27060389

[2]: https://www.ncbi.nlm.nih.gov/pubmed/24386671

[3]: https://www.reddit.com/r/ketoscience/comments/7o54yh/longterm_keto_study/

[4]: https://news.nationalgeographic.com/news/2011/06/110623-iceman-mummy-otzi-meal-goat-stomach-science/

[5]: https://news.ycombinator.com/item?id=18132096

[6]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989112/

[7]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/