It isn’t that strange. It’s basically keto, which has become almost mainstream.
For the record, I’ve tried the “zero carb” diet (basically meat) and it’s not that hard once you treat food as purely as something functional like a vitamin rather than a source of pleasure.
As far as I know, Peterson's diet is actually his daughter's diet [1]. She claims it cured her from numerous diseases including rheumatoid arthritis and depression [2].
I have no idea how credible that is, but I'm just saying it isn't something he decided on a random basis just to look cool.
keto is about high fat and entering ketosis; if you eat just meat you'll have enough protien that through gluconeogenesis it will be converted into glucose and it will knock you out of ketosis.
For the record, I’ve tried the “zero carb” diet (basically meat) and it’s not that hard once you treat food as purely as something functional like a vitamin rather than a source of pleasure.