Digestion efficiency of intermittent fasting?

I wanna know if we absorb more of what we eat doing IF or with your average 4 meals per day. My intuition tells me our digestive system would be more efficient with higher meal frequency and smaller quantities of food. But maybe we spend more calories keeping our digestive system active all day long? I can't imagine our organs being able to absorb all the food in one take but when you spread it out in smaller portions should be easier? I'm not asking this from a dietary perspective, just from an efficiency point of view. Having a limited amount of calories to consumer per day, what would be the smartest choice to absorb most of it?

Answer

In a nutshell….

When the SCN starts speeding up due to melanopsin triggering, our system is turned on. All of this happens as soon as we see daylight in the morning. So in theory if you ate breakfast you would benefit from the bolus of food hitting your system at the time the system is full swing. As the SCN slows down as blue light exposure wans in the evening, if we stop eating near dusk it would mean that we are not running food through digestion while our pancreas and liver were starting to cool off. This would result in a great night’s rest. Since no food is coming your body would perform “Metabolic Switching” through the night and carry on into the morning. At the point of “Metabolic Switching” the body would have done everything it could from digesting the contents of the upper portion of the gut and then microbiome would continue through fermentation to get every last nutrient from the meal. This process in my estimation is about 26 hours long.

Eating more will make you poop more which shortens the time the food has in your system.

For clarity, these are my thoughts as I have arrived to these conclusions from reading a number of papers on human physiology and my own lived experience. I am no expert.