I'd shoot more for 2 days. A lot of people do this with fasting. One major benefit is metabolic flexibility. You're exposing your body to different fuel sources and forcing it to utilize them.
The only caveat to trying this would be try to not make it a 5 days on, 2 days off thing, routinely. Randomize it.
Kiefer's carb nite does the mirror of that (low carb 6 days and more carbs 1 day):
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