A bit informal but gets the gist across: eating outside of a 12 hour period (which begins at the first meal of the day) causes increased fat uptake, lowers insulin sensitivity, and your muscle starts to waste.
When equated for calories, protein, and fiber (and their "Calories Out" side effects) there is no statistically significant difference in diets from the twinkie diet[1], keto, low carb, low fat (though not too too low cause of hormones), one meal a day, 12/12 or 16/8 or 5d/2d intermittent fasting...