Ernest Hemingway had the right idea when he said:

“I love sleep. My life has the tendency to fall apart when I’m awake, you know?” – Hemingway

Indeed, good (7-8 hours long) sleep works like a blessing, mostly to your brain. Your brain is bombarded with tons of stimulants every day. A decent night’s rest, besides rebooting your brain and consolidating your memories and experiences [1], also regenerates tissues throughout your body. That is why having inefficient or chronically disrupted sleep puts you at risk of serious diseases including cancer, obesity and type 2 diabetes [2].

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If you are diabetic or have another metabolic disease, disease-associated complications may also prevent you from fully taking advantage of your night’s rest [3], thus generating further health problems. Read on to learn more about what you can do to sleep better as someone with diabetes or high blood sugar.

Have you ever eaten or had a drink right before bed, only to wake up later that night, restless? Both late-night snacks and alcohol can disturb your sleep and circadian rhythm.

What makes us sleep?

A master biological clock in your brain, along with associated internal clocks in various tissues of your body, gives your body and its processes (like food digestion and metabolism) a natural circadian rhythm. This circadian rhythm is divided to different stages within 24 hours. Your circadian rhythm regulates your wake-sleep activity and makes you feel like it is high time to go to bed when the midnight hour approaches (unless you are a super late-night owl, naturally adjusted to late hours activity!).

Your circadian rhythm is a complicated system, driven by internal clocks situated in your brain and some peripheral tissues [4]. This rhythm affects your cells by tightly and timely regulating the release of hormones, proteins (like insulin and cortisol) that act as chemical messengers throughout your body, preparing it for various activities depending on the time. For example, the “stress” hormone cortisol peaks early in the morning to help you start your day!

The main hormone responsible for sleep is melatonin. This hormone is a “sleep-on” signaling molecule produced in a small part of your brain called the pineal gland. Melatonin secretion is coordinated by the light/dark cycle – as it gets dark outside, your brain usually releases melatonin. That is why we usually fall asleep more easily when melatonin release is at its peak (when it is dark outside – and in your house!).

Melatonin molecule.

If the sleep hormone melatonin is regulated by the light/dark cycle, then why do some of us struggle with sleep at night?

What do these hormones and your circadian rhythm have to do with disrupted sleep? There are many things that can disturb, delay or otherwise change your circadian rhythm and internal clocks, and thus affect your sleep. This includes sunlight exposure and stimulants like caffeine!

There are many things that can cause you to get inefficient sleep, from consuming caffeine in the afternoon, to eating late at night, to not getting sunlight early in the day and getting too much blue light from electronic screens at night, to consuming too much sugar, to shift work. Shift work (or working nights and days, on and off) like jet lag throws off your circadian rhythm. In a vicious cycle, a disrupted circadian rhythm can lead to more inefficient sleep (and increased hunger – more on that in a bit). This inefficient sleep is usually too short.

What’s the deal with lack of sleep, diabetes and weight gain?

Now you know that not getting enough sleep or getting low quality sleep, for example from a shift work schedule, is related to a disruption in your circadian rhythm. But the consequences of this go beyond your sleep/wake cycle.

Your circadian rhythm is not only important in regulating your energy levels and sleep pattern throughout every 24 hours, but is also important in regulating your metabolism, particularly through tightly timed secretion of hunger hormones and insulin. Insulin is a hormone that helps control your blood sugar levels. Thus, circadian disruption can lead to more blood sugar spikes and crashes and weight gain, ultimately putting you at risk of obesity and type 2 diabetes.

Poor sleep, or not accomplishing your body’s needs for regeneration (your body typically needs 7 to 8 hours of sleep per night) can put you at risk of developing type 2 diabetes and its complications, but can also put you at risk of obesity. This is because sleep duration affects your metabolism. A group of Spanish scientists [7] showed that the incidence of obesity over an 11-year follow-up increased in people with fewer hours of night-time sleep.

But how exactly does circadian rhythm disruption lead to weight gain and metabolic disease? It may be related to impaired timing and amount of food intake [2].

A disrupted sleep/wake cycle (staying awake for too long) can naturally lead you to seek more energy – you invest in eating instead of sleeping. Staying up late means that you probably eat later into the night. But not getting enough sleep can also make you crave sugar and eat more the next day.

Inefficient sleep also impairs your energy balance, causes inflammation and leads to poor glucose tolerance and poor insulin sensitivity [2]. You might remember from my previous blog posts that inflammation, poor blood sugar control and insulin resistance are associated with type 2 diabetes.

We usually associate poor sleep and metabolic disease with advanced age. But it turns out that even young people can have an increased risk of developing diabetes when they are sleeping poorly (meaning they do not sleep enough to feel rested and they experience daytime sleepiness). Their risk of developing diabetes as a result of poor sleep is even higher if they are already suffering from obesity and/or having problems with breathing, such as in obstructive sleep apnea, where people’s breathing repeatedly stops and starts during the night [8].

Low quality sleep is associated with greater fluctuations in your blood glucose (blood sugar levels), especially if you have or at risk of diabetes. A study published by a Japanese group [9] indicates that poor sleep leads to more frequent blood glucose crashes (hypoglycemia) in patients suffering from type 2 diabetes, at various time of the day, not only at night. This is dangerous and may even result in death if blood glucose is too low.

In a vicious cycle, having type 2 diabetes in turn impacts your sleep, leading to even more inflammation and poor health. Type 2 diabetes-related sleep disorders result from diabetes itself or from secondary complications of this disease such as obesity or heart diseases [10].

Sleep for your heart

Sleep, or the lack of it, can also impact your heart health. If you already have type 2 diabetes and additionally do not sleep enough, you also risk having highly unwanted cardiovascular complications. For example, Meng and colleagues [11] concluded that poor sleep is a plausible risk factor for coronary vascular disease (CVD) in type 2 diabetes patients. Increased inflammation may play a role in this increased risk for CVD as a result of poor sleep.

On the other hand, Li and colleagues [12] observed that men with a history of smoking, high blood pressure, high cholesterol levels and long sleep duration had a significantly higher risk of coronary heart disease (CHD). It seems from new research that both long sleep duration (more than 9 hours) and short sleep duration (less than 6-7 hours) can be harmful to your health. This may be because whether you are getting too much or too little sleep, you are disrupting finely tuned circadian rhythms in your body that regulate your metabolism and hunger levels.

Not too much. Not too little. Just enough.

What’s the overall conclusion from these studies? If you want to have sweet dreams and enough of them, keep a consistent sleep pattern and do not smoke or eat late at night! Simply provide yourself with a decent night’s rest of a reasonable duration (7 to 9 hours) and ideally keep your sleep timed with the sunlight like the famous song’s words suggest: “Sweet dreams till sunbeams find you”.

Keeping your food intake limited to sunlight hours will also help reinforce your natural circadian rhythm, as both sunlight but also food availability set your internal clocks. This is also called time-restricted eating– and it improves cellular recycling or autophagy.

There is no better way to keep your biological clock and circadian rhythm under control and thus to keep yourself healthy – than getting enough sleep!

For more information on sleep and sleep tips, see the LIFEApps Sleep FAQ here. Have sleep questions? Connect with a sleep expert via LifeOmic Connect, which you can find in our LIFE Extend app (within the Sleep Pillar) and on this and other sleep-related blog posts, in a pop-up in the lower right-hand corner!



  1. Goerke et al. J Neural Transm, Vienna, 2017
  2. Depner et al. Curr Diab Rep., 2014
  3. Bayon et al. Ann Med. 2014
  4. Rosenwasser et al. Sleep Med Clin., 2015
  5. Dubocovich et al. Sleep Med. 2007
  6. Kecklund et al., BMJ, 2016
  7. Gutiérrez-Repiso et  al., Sleep Med. 2014
  8. Mokhlesi et al., Pediatr Diabetes, 2019
  9. Hayashino et al., Exp Clin Endocrinol Diabetes. 2013
  10. Khandelwal et al., Indian J Endocrinol Metab. 2017
  11. Meng et al., J Diabetes Complications. 2015
  12. Li et al., Diabetes Res Clin Pract. 2017