Same meal, different time, different spike

What your internal clock has to do with glucose

How circadian rhythm impacts metabolic health

A recent podcast guest told us "You literally have a different body at different times of day." She was referring to the shifts in hormones that happen solely based on time of day.

For example, in one Harvard study, researchers had people eat breakfast at 8 am and dinner at 8 pm, then completely reversed it, shifting breakfast to 8 pm and dinner to 8 am with sleep moved to daytime. No matter when people actually ate or slept, glucose spiked 17 percent higher in the evening.

That's not about willpower or food choices. It's your circadian rhythm, the internal clock that governs when your body is primed to handle glucose well and when it isn't. Light exposure, sleep timing, and meal timing all feed into this system, and when they fall out of sync, blood sugar control suffers even if your diet stays exactly the same.

The circadian connection →

Five Key Takeaways

1. Natural light cues your body’s regulatory system.

Light hitting your eyes triggers brain processes that direct the release of hormones controlling, among other things, hunger and blood sugar levels.

2. Late-night light exposure is linked to worse blood sugar control.