Optimized is probably everyday, one meal a day basically since you can use the autophagy every day and get the nutrients you need in the meal. And if you need more because you went to a buffet or something you can add a day or two.
This makes sense from a primal standpoint too since you wouldn’t want to let food rot to split it up into 3 meals, you’d just eat it all fresh after a hunt. And then some days (mostly in winter) where they can’t catch prey they just don’t eat.