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Healthy Weight

2 Sleep Patterns That Might Be Wrecking Your Blood Sugar

Ava Durgin
Author:
Ava Durgin
September 23, 2025
Ava Durgin
Assistant Health Editor
By Ava Durgin
Assistant Health Editor
Ava Durgin is the Assistant Health Editor at mindbodygreen. She is a recent graduate from Duke University where she received a B.A. in Global Health and Psychology. In her previous work, Ava served as the Patient Education Lead for Duke Hospital affiliated programs, focusing on combating food insecurity and childhood obesity.
Cropped Photo of a Woman Sitting on a Bed
Image by Guille Faingold / Stocksy
September 23, 2025

We often think of sleep as time “off,” but behind the scenes, your body is doing some of its most important work. From hormone release to tissue repair, the overnight hours are a cornerstone of health.

And now, new research1 shows that your sleep schedule may also play a bigger role in blood sugar balance than most people realize.

Sleep & metabolism: An overlooked connection

Blood sugar health isn’t just about what’s on your plate; it’s also about how well you sleep. In fact, researchers analyzing continuous glucose monitor (CGM) data found that people with chronically inadequate sleep or late bedtimes had significantly greater fluctuations in blood sugar levels compared to those with more consistent and sufficient sleep.

Why does this matter? These blood sugar swings, known as glycemic variability, are linked not only to type 2 diabetes but also to cardiovascular disease and overall metabolic health.

In other words, the stability of your glucose may be just as important as the average level.

Key takeaways from the study

Here's what the researchers found:

  • Short sleep disrupts glucose stability: Those with persistently poor sleep duration had the greatest blood sugar fluctuations.
  • Late nights carry a cost: People with consistent late bedtimes showed higher glycemic variability, even if their total sleep wasn’t dramatically shorter.
  • The combo is the worst of all: When inadequate sleep and late sleep onset overlapped, the negative effects compounded.

It’s not just how much you sleep, but also when you sleep that influences how your body regulates glucose.

Glucose, sleep, & longevity 

Glycemic variability is emerging as a strong predictor of long-term health. Wide swings in blood sugar can tax the cardiovascular system, increase inflammation, and interfere with restorative sleep, setting up a feedback loop that makes both sleep and metabolism harder to regulate over time.

This is where circadian alignment comes in. Going to bed earlier helps keep your internal clock in sync, which supports cortisol and melatonin rhythms, nighttime repair processes, and glucose regulation.

The takeaway

Think of sleep as part of your metabolic toolkit, just as essential as nutrition and movement. Prioritizing both enough sleep and an earlier bedtime could be one of the simplest, most accessible ways to stabilize blood sugar and protect long-term health.