Good morning!
I hope you’re all having a peaceful weekend.
Did you know?
ONE night of poor sleep (not enough of it and/or poor quality) can give you the blood sugar of a Type 2 Diabetic the next day?
**read that again**
And you wonder why you crave sugar and carbs so much when you’re tired 🤔 This is not your lack of self-control at play – this is a physiological response from your brain saying, “I need energy and I need it now.” It will seek out the foods that it knows will offer the quickest energy – aka sugar.
This is one of the reasons many people who sleep poorly, consistently, have a tough time losing weight and/or obtaining their health goals.
If you’re not already – I hope this information prompts you to prioritize your duration of sleep + sleep quality. The article I am sharing today discusses how light exposure is one of the number one ways we disrupt our sleep quality and therefore lead to insulin resistance (aka Type 2 Diabetes) – PLEASE take a moment to soak this information in: your sleep hygiene can cause blood sugar issues JUST AS MUCH as what you eat // don’t eat, workouts, stress management, etc. It is THAT important.
Okay, I digress… Keep reading >>>
A recent study (which I cannot get the link to work for, so if you want to read it – copy and paste the link below >> I suggest reading the top portion titled: Significance – 1 min read if you do not care to read the whole study) assessed an entire nights exposure to a moderate light compared to very low level light, and measured metabolic changes in participants.
https://www.pnas.org/doi/10.1073/pnas.2113290119
Some details on the study if you don’t want to dig into the science:
- The study assessed young adults sleeping in two different conditions: the first group was with very minimal light (the equivalent of moonlight); the second group had exposure to light equivalent to a very dark day or dim indoor lighting (depending on the height of a night lamp, this would be roughly equivalent).
- After only one night, the group that was exposed to the brighter light experienced reduced insulin sensitivity (aka higher blood sugar), reduced slow wave and REM stage sleep (aka less quality sleep = you’re waking up groggy), higher heart rate (aka can lead to higher cortisol // stress hormone), and lower heart rate variability (HRV) (aka you will recover less efficiently from workouts, have a more challenging time responding to stress)
- It is plausible that disruption to sleep quality had a big impact, however other studies (like this one) have found that in people who were forcibly kept awake, those who were kept awake in light conditions experienced more metabolic dysregulation than those kept awake in dark conditions.
- Additional studies (like this one) have found that light exposure activates the sympathetic nervous system, causing changes in cortisol, melatonin, and glucose regulation. Therefore a number of mechanisms are likely to be at play.
- In addition to light exposure during sleep, bright light exposure prior to sleep is also associated with negative outcomes, with one study finding standard home night lighting was bright enough to suppress melatonin levels by 50%.^^READ THAT AGAIN^^
- Net, net > minimizing light exposure before bed and ensuring a dark sleeping environment (aka no night lights, lamps, TV’s on) is important for sleep quality and for metabolic health.
- I suggest reducing nightly light exposure 90+ minutes before bedtime. You might be thinking, “But what if I want to watch TV or scroll social media or send a text?” Glad you asked! This is where those sexy Blue Light Blockers I put on your meal plans and talked about here a few months back, come in really handy. And now that you understand how IMPACTFUL light can be to your sleep quality – I bet those glasses just got a lot sexier 😉
- And last but not least – ensure a dark sleeping environment through the use of an eye mask or blackout shades. At the VERY least, turn your TV’s, lamps, etc. completely off.
A nudge for one big intention this week: prioritize your sleep – duration, quality and hygiene (including night time light exposure).
As always, I’m here for questions!
Wishing you all a RESTFUL week!
Alix