Are you losing sleep due to sugar?

hangover sleep sugar May 03, 2021

It wasn’t long ago that we were being advised to cut back on salt. Then, we were told to cut back on sugar because researchers linked it to obesity, type-2 diabetes and a raft of other health problems.


Since 2016, the general advice has been to drop sugar from your diet altogether. This is, of course, not easy as so many of us have a ‘sweet tooth’, thanks to diets that are rich in sugary tastiness. Unfortunately, the more sugar we have eaten over the years, the more our body craves it now.


In Australia around 74% of foods available in the grocery stores or supermarkets contain added sugar (1), and it’s estimated that the average Australian consumes 18 teaspoons of sugar a day. This is higher than the recommendation from the World Health Organization (WHO) who suggests the recommended maximum daily sugar intake is 12 teaspoons a day, which is also on the high side.


If you’re thinking, I’m ok because I use sweeteners, unfortunately artificial sweeteners are not safer. In fact, they can also disturb sleep.


What is sugar?

Sugar is a simple carbohydrate because it is in its’ most basic form. It can be added to foods including, sugar in sweets, desserts, processed foods, and regular fizzy drinks. It is also found naturally in fruits, vegetables, and milk.


Complex carbohydrates, which are starches and fibers, are considered complex because they contain multiple simple sugars.


According to a 2016 study, a diet high in sugar and carbohydrates has been shown to make people feel sleepy and fall asleep faster (2), but it also causes poor sleep quality (3) and more night time awakenings (4).


Sugar and poor sleep

Diets high in carbohydrates elevate levels of tryptophan, an amino acid which promotes sleep. Sugar suppresses orexin, a neurotransmitter which is responsible for alertness. So even if sugar makes you sleepy initially, and gets you off to sleep, it appears to lead to a lower proportion of restorative deep sleep which could result in night-waking or waking in the morning feeling groggy with a sugar-hangover.  


If your diet during the day is characterized by high sugar levels, you may find you have a tendency to eat food later on in the day because of your rollercoaster sugar levels. This will also affect your sleep.


Researchers have investigated high-carb diets with a larger proportion of simple sugars. The idea being the simple sugars can readily be burned to provide immediate energy. The result is that people spend less time in deep sleep and more time in Rapid Eye Movement (R.E.M.) where they can burn the excess energy. The R.E.M. phase of sleep uses the most energy and so the body adapts and stays in this phase longer to burn the excess energy, shortening the deep sleep or restorative phase of sleep.  


Sugar and night waking

When you eat sugary foods, your blood sugar levels rise and your pancreas releases insulin to process it. This helps the sugar to be taken back into your cells and can result in overstimulation, making you ready for activity when you’re meant to be preparing for sleep. The poor sugar regulation, due to eating too much sugar for your body to process, can cause your blood sugar to dip in the middle of the night, causing you to wake up. Some people may wake feeling shaky – and will need to go get something to eat to stabilize their blood sugar in the middle of the night. Others may find that they need to get up and go to the bathroom several times at night. This could be a sign that the kidneys are working overtime due to elevated blood sugar levels.


Sadly, in all of these situations you will have poorer sleep, yet you will wake craving more sugar the next day. And the vicious cycle of sugar, energy, and poor sleep quality is set up.  


How to counteract the sugar impact

Apart from reducing your sugar intake, which should be your goal if you have disrupted sleep, there are other things you can do to lessen the impact of a high sugar diet in the meantime.



Sugar uses up a lot of magnesium which is needed to produce melatonin and activate your parasympathetic nervous system which is the system that calms you down in the evening and prepares you for sleep. To assist your body, you may want to consider increasing your intake of foods high in magnesium or take a supplement.  



Tryptophan is used in the production of serotonin which is a hormone that controls wellbeing and happiness and enhances sleep. Foods high in tryptophan are beans, lentils, nuts, whole grains, poultry, dairy and lettuce.


Fibrous foods
Choose fibrous foods to eat, like wholemeal and granary breads, bran muffins, berries, broccoli and potatoes in their skins.


The less you rely on caffeine and sugar during the day, the more you are able to achieve healthy sleep patterns at night.


If you need more motivation to cut back on your sugar, a high sugar intake is also linked to depression, obesity, high blood pressure, increased risk of heart attack, fatty liver disease, diabetes, cancers and tooth decay.



 1. Journal of Insulin Resistance ISSN: (Online) 2519-7533, (Print) 2412-2785

2. Nutritional effects on sleep - PubMed (

3. Low intake of vegetables, high intake of confectionary, and unhealthy eating habits are associated with poor sleep quality among middle-aged female Japanese workers - PubMed (

4. Fiber and Saturated Fat Are Associated with Sleep Arousals and Slow Wave Sleep - PubMed (



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