For healthy young adults, staying awake four extra hours after eating a late dinner does not lead to higher blood sugar levels than going to sleep at the usual time after the same meal.

Eating dinner late relative to the body's natural melatonin rise raises blood glucose levels after eating by about 15% in young adults, regardless of whether they sleep late or at their usual time. This suggests that when you eat matters more for blood sugar than when you sleep.

Eating most of your daily calories later in the day is associated with reduced ability to regulate blood sugar and poorer sleep quality.

Eating meals later at night leads to higher peak blood sugar levels after eating and lower fat burning compared to eating the same meals earlier in the evening, even when total calories are the same.

Eating meals later in the day leads to a measurable increase in blood glucose levels after eating, even in people who are otherwise metabolically healthy, due to the timing of eating relative to the body's internal clock.

Eating dinner later than usual, relative to a person's internal body clock, raises blood glucose but does not significantly change insulin levels after the meal. This suggests that the body's insulin response becomes less tightly linked to glucose changes under circadian misalignment.