There has been considerable research on the relationship between circadian biology and metabolic function. As humans, we are diurnal animals whose daily rhythms are integrally linked to the sun. We rev up in the morning and wind down in the evening. Consequently, our digestive systems and metabolic machinery function best during daylight hours. You’ve probably noticed that you don’t have much of an appetite if you wake up extremely early in the morning. Or that a late-night meal wreaks havoc on your digestion and sleep quality. All of this is very well known.
Eating when the sky is light does more than just aid digestion. If you envision most of your internal workings as a large and complex manufacturing plant, bringing the food in during the day is like running that factory when the lights are on. Let’s leave the brain out of this discussion because it’s highly active at night. Most of those metabolic conveyor belts and machining operations run best when all the workers are at their stations during the day.
There are obviously going to be exceptions to this policy. For example, if you live in Alaska during the winter…you only have a few hours of daylight available. It may be very challenging to consume all your food in that fairly narrow window. But overall, eating when the sky is light can improve nutrient delivery and decrease fat storage.