Here's a totally non-sarcastic pro tip for anyone starting a diet in the new year: Just shut the fuck up about it. You gain nothing by announcing you're doing keto, whole 30, or whatever else, unless you just really need a peanut gallery of people telling you why diet X is bad.
I did keto for almost five years. I just told people I had a gluten allergy, which no one ever questioned. Friends of mine who announce they're doing keto on FB, comparatively, get fuckin' lambasted by the armchair crew.