Sleep and blood sugar
What we eat, our blood sugar levels and sleep are all different sides of the same coin. On one side blood sugar has a significant impact on your sleep patterns, while on the other poor sleep will directly impact your glucose levels. Short sleep duration (less than seven hours) can have a significant impact on your health. Adults who are short sleepers are more likely to have chronic health conditions like diabetes, obesity, or heart disease. So, getting control of your sleep habits can positively affect our health and longevity.
Of course there are many areas to look into in order to improve sleep, but today we will discuss how you can start by managing th relationship with blood sugars.
Sleep effects on blood sugar
The relationship between sleep and blood sugar levels is complex. Sleep is essential to allow your body to restore and repair itself. and when we don’t get enough sleep, several changes occur. Let’s have a look.
Sleep impacts insulin levels
Sleep affects your hormone levels and your circadian rhythm. Your circadian rhythm naturally controls your sleep-wake cycle and keeps in check our internal clocks.
Let here take a small pause and tell you about something you probably don’t know. Our internal clocks are always running and they are independent of light or dark! They have a duration of around 24 hours and 15 minutes. Where light comes to play is to reset our clocks every day so it doesn’t start drifting off. If you are interested look up for the experiment of Jean-Jacques d’Ortous de Marain in 1729 and that of Pr.Kleitmanin 1938.
So, this internal clock controls hormone secretion, temperature, eating habits, and digestion. Sleeping properly, keeps our circadian rhythm in check which in turn regulates metabolism, insulin, and blood glucose. This is pretty important so let me repeat. Your circadian rythm controls criticial function in your body day-in day-out.

When your circadian rhythms are out of sync, your body’s metabolic health can decline—and a risk for diabetes can increase. This is well researched. Sleep deprevation leads your body to produce more insulin to stabilize blood glucose levels. The more insulin resistant your cells become, the greater the risk that your insulin and blood sugar levels will chronically rise. This eventually leads to glucose intolerance and diabetes.
Sleep regulates hunger hormones
One of those hormones is leptin. Leptin plays several roles within your body. Two of its key jobs are long-term energy regulation and metabolism. You may have heard it referred to as the starvation or satiety hormone. The fat cells in your body release leptin, telling your brain when you have enough energy. When released, it suppresses your appetite, making you feel satisfied. If leptin levels are low, your appetite increases.
Short sleep duration reduces leptin levels, leading to overeating and weight gain. In turn, the craving to eat more results in an increased intake of carbohydrates which raises glucose levels.
Sleep impacts sympathetic nervous system
Sleep deprivation is a big stressor and releases stress hormones like cortisol. In-turn overly active, it can reduce insulin secretion and promote insulin resistance. Both of these can lead to chronically raised blood sugar levels.
Sleep modulates inflammation
Sleep deprivation increases inflammation levels. Again if inflammation is chronically high, it can lead to lifelong conditions such as metabolic syndrome, type 2 diabetes, heart disease, and obesity. Without sleep you will have a very difficult time to heal and recover from anything.
Statements
- Sleep is so important that it has survived million of years of evolution.
- Sleep is so important that every single species sleeps even at the risk of being attacked during sleep.
- Lack of sleep increases the risk of metabolic syndrome, diabetes and more.
Blood sugar effects on sleep
As we said the relationship works two-ways. Poor blood sugar management will impact your sleep.
Let me here make another little pause, and highlight that any late night dinner should be totally avoided. The earlier you eat the better sleep you will have. This has to mainly to do that we avoid our digestive system having to work very hard when the whole body should be winding down and preparing us for sleep. Aim to have your last meal around 3 hours before going to bed.
Waking-up during the night?
Late night snacking, fast food before bed blood sugar levels can affect the nervous system, making it hard to fall and stay asleep. This can trigger insomnia and increase cortisol and adrenaline levels, preventing your body from fully relaxing. You may need to go to the bathroom more often due to your kidneys trying to flush the excess glucose out of your body. High blood sugar can lead you to feel dehydrated, waking you from your sleep to rehydrate with a glass of water. They can also cause you to feel hot, irritated, and unsettled, making it difficult to sleep.
One the extreme of high blood sugars is low levels due to stress, alcohol, insulin resistance but not only. Low blood sugar levels can affect your sleep in the following ways: They causes the release of cortisol and adrenaline. These hormones wake you up and stir your appetite. When trying to raise your blood sugar levels back to normal, your body overreacts by increasing your appetite. If you then eat when you should be sleeping, it can upset both your glucose levels and sleep-wake cycle. Low blood sugar levels can further disrupt sleep by causing, nightmares, sudden waking, and sweating.
Glucose reference range
- Glucose levels when asleep between 70-100 mg/dL
- Optimal morning fasting glucose values between 80-100 mg/dL
Sleep patterns
Sleep deprivation

Sleep fragmentation
Sleep insufficiency
Final thoughts
- Proper Sleep and blood sugars level are both at the center of health and as so many things in health one affects the other is various ways.
- Try to eat 3-4 hours before bed a nutritious whole food dinner without stressing your gut or spiking your blood sugars too high.
- Try to tune in to your circadian rythm, and sleep for around 8 hours. 10-11pm is a good target to go to bed. And don’t forget to give a chance to your mind and body to wind down.
- Measuring your blood glucose on a daily basis even if healthy has many benefits. Try keto-Mojo or if you want to get insights throughout the day a continious glucose monitor (CGM) like FreeStyle Libre.
- Check-out the ketOntrack Sleep Series
- Modulation of glucose regulation and insulin secretion by circadian rhythmicity and sleep
- Impact of sleep and sleep loss on glucose homeostasis and appetite regulation
- Associations between Poor Sleep and Glucose Intolerance in Prediabetes
- Sleep disorders and the development of insulin resistance and obesity