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Nutrition and Sleep

Sleep is critical to our health. So critical that optimising sleep should be at the core of all health management plans. 

You could have a stellar diet and move your body daily, but if you aren’t getting high-quality sleep on most (if not all) nights, then you’ll have a tough time reaching your health goals.

Unfortunately, modern lifestyles are disrupting our ability to fall asleep and wake naturally. 

With artificial light stimulation, courtesy of the screens we look at all day long, our bodies are tricked into thinking it is still day-time long after the sun has gone down. I’d bet that hardly any of us can even remember what it feels like to wake up when our bodies are ready to – that means, without a piercing alarm jolting you out of bed. 

With this in mind, you think you don’t have a problem with sleep – but, do you truly know what it feels like to sleep well without interruptions?

Why is Sleep So Important?     

Simply put, sleep provides our bodies with an opportunity to repair, regenerate and grow. For example, a big session at the gym won’t be very effective in building new muscle if you don’t get enough healthy sleep that night. 

But, poor sleep steals us of far more than a little muscle mass. 

Chronic sleep restriction can result in elevated sympathetic nerve activity and a less efficient insulin response (i.e., insulin resistance).  This is a recipe for metabolic disaster and can increase one’s risk of thyroid issues, diabetes, obesity and to top it off – perpetuate the sleep-stress cycle (making it even harder to get a good night’s sleep!). 

Here are some ways that chronic sleep restriction can negatively affect your health:

“Sleep loss due to voluntary bedtime curtailment has become a hallmark of modern society… Chronic sleep loss, [whether] behavioral or sleep disorder related, may represent a novel risk factor for weight gain, insulin resistance, and Type 2 diabetes.” — Spiegel, K. 

The role of nutrition in sleep is not well-studied. But that doesn’t mean we can’t put our thinking caps on and use science and logic to figure out how we can enhance our daily routines to promote better sleep! 

When it comes to harnessing nutrition to improve sleep, there are two overarching factors we need to consider: melatonin and toxins.


Melatonin is our sleepy hormone and responds predominantly to light. The ideal scenario being that, when the sun goes down, melatonin production goes up. 

However, our modern lifestyles are exposing us to things like artificial light, night work, and stress (among other things), which disrupt and override our natural sleep-wake cycle. This means many of us are not producing adequate melatonin to get the deep rest we so badly need – and deserve! 

Of course, allowing yourself to wind down and dim the lights as night rolls in are useful strategies. But these aren’t necessarily easy, and not always enough. For those of us who have pushed the boundaries of sleep for so long, we need more.  

To produce adequate melatonin in the body, we need three things: adequate serotonin, tryptophan and energy (specifically, a small amount of glucose). 

Vitamins and minerals also play a role in their own indirect ways (e.g., magnesium, zinc, folate, etc.) and therein, achieving nutritional adequacy (i.e., identifying and treating any micronutrient deficiencies) must also be attended to. 

For personally tailored advice on achieving nutritional adequacy or for effectively implementing any diet or lifestyle change to improve your sleep, it is recommended you seek support from an Accredited Practicing Dietitian or appropriate medical professional. 


Serotonin can be thought of somewhat as the “opposite” to melatonin. It is the hormone that we want beaming throughout the day to energise and motivate us, as well as to prevent us from falling asleep at our desks or chucking tantrums when things get hard (i.e., it has a mood stabilising effect)!

As the day comes to an end, your body starts converting serotonin into melatonin to help you wind down and prepare for sleep. So, implementing strategies to optimise sleep must begin during the day. 

Exercise is a well-known serotonin booster and participating in 15-30 minutes of your favourite movement activity (preferably outdoors in the sunlight) can promote the level of serotonin you have floating around. 


Tryptophan is an essential amino acid (a building block of protein) that is found in most protein-rich foods. The body uses tryptophan to synthesize both serotonin and melatonin. So, getting enough tryptophan through your diet is a double-whammy for promoting a good night’s sleep! 

Most of us should be aiming for around 1-2 servings of protein-rich foods at each meal. Some ideas of what one serve of protein looks like are: 

  • 65 grams (g) cooked red meat such as beef, lamb, veal, pork, goat or kangaroo 

  • 80 g cooked poultry such as chicken or turkey 

  • 100 g cooked fish fillet / seafood or one small can of fish

  • 2 large (120 g) eggs

  • 1 cup (150 g) legumes/beans such as lentils, chickpeas or split peas 

  • 170 g tofu

  • 30 g nuts, seeds, peanut or almond butter or tahini or other nut or seed paste 

  • 40 g cheese 

Energy Availability

With that said, our body can make all of the glucose it needs through the breakdown of proteins and fats, so eating carbohydrates is not an essential component of every diet - but hey, drinking a glass of milk before bed is worth trying if you are struggling with chronic sleep deprivation! 

Well, human fasting studies have shown that short-term fasting by total rejection of food or with very limited intake of energy from 2 to 7 days reduced melatonin concentration in the blood by about 20%.  

The reason for this likely boils down to the fact that we need a small amount of glucose to produce melatonin (and serotonin for that matter), and glucose supplementation during short-term fasting has been shown to return the decreased melatonin concentration to normal.

We also know that our brain uses glycogen (stored glucose) as fuel during the night. Our main source of glucose is dietary carbohydrate. This may be one reason as to why a glass of warm milk has long been touted as an effective sleep remedy before bed-time. The carbohydrate in milk (lactose) splits into glucose and galactose in your body. This glucose might just be the thing that tips your body over into sleep-mode by enhancing the production of melatonin.

With that said, our body can make all of the glucose it needs through the breakdown of proteins and fats, so eating carbohydrates is not an essential component of every diet - but hey, drinking a glass of milk before bed is worth trying if you are struggling with chronic sleep deprivation! 

With consideration of the above, restrictive low-energy/low-Calorie diets (common approaches for weight loss) might be causing harm to your sleep – along with many other aspects of your hormonal and physiological health! So, take a break from the fasting and low-Calorie diets if you aren’t getting the restful shut-eye you are so craving.


As increasing research into the gut-microbiome improves our understanding of gut health, we are beginning to learn more and more about the influence of bacteria and toxins on our ability to achieve healthy sleep. 

Connections have been found between sleep deprivation and poor gut bacteria in animals. In rats, bacterial infections often travel to the gut, where the toxins can cause sleep deprivation. 

Whether this proves to be true for humans or not, we are continually being reminded that “it all starts in the gut”! So, how can we eliminate toxins and improve our gut health for all-round good health? 

1. Eat a whole-foods based diet

Following a diet that is low in nutrient-poor processed and sugary foods, and high in nutrient-rich whole-food proteins and healthy fats, is a sure-fire way to reduce your toxic load and support a healthy gut. 

2. Add salt

If you’re following a whole-foods based diet, you may need to add salt to your meals to ensure you are getting enough sodium. Sodium is an essential mineral that plays an important role in your digestion and gut health. Sodium deficiency can lead to uncomfortable gut symptoms such as bloating, constipation, diarrhea and reflux/indigestion.

3. Discover glutathione

Glutathione is a powerful antioxidant and natural detoxifier. It plays a critical role in clearing your body of toxins, protecting fats from oxidation (damage), and promoting healthy immune and brain function. It does all of this by enhancing the function of your liver!

Due to lifestyle factors such as stress and poor dietary choices, many people likely have lower than optimal glutathione levels, which could be affecting their sleep. 

Glutathione is found in sulphur-rich foods including garlic, onions, and cruciferous vegetables such as broccoli, kale, collards, cabbage and cauliflower. Glutathione is also synthesized from cysteine, found in dairy protein (milk is starting to look like a bit of a sleep-warrior!). 

4. Include healthy fats

Consuming fat is the only way to increase your bile turnover - a major way that your body removes toxins that might be affecting your sleep. 

Try some oily fish at dinner, add a little grass-fed butter to your steamed veg, or drizzle macadamia oil over your salad. 

5. Aim to increase your alcohol-free days

Alcohol is a toxin that can also negatively affect your ability to produce melatonin – a double negative for sleep health. 

I’m not saying you have to give up alcohol, but increasing your alcohol-free days by one to two days each week could see some positive changes to your sleep health.

Why not replace the alcohol with a glass of soda water, fresh lime, and mint, or treat yourself to a relaxing lavender, bubble-bath with magnesium Epson salts instead! Surely, the pure thought of that is making you sleepy!

The Bottom Line?

This post contains a variety of nutritional strategies that may improve your sleep quality and overall sleep health. However, as always, it’s important to recognise that what works for one person, may not work for the next. 

Nevertheless, knowledge is power and improving your health-understanding will help you to increase the number of tools that you have in your health-toolbox. 

I also will always recommend that you gain individual support from a trusted healthcare professional who can help you implement diet and/or lifestyle strategies that are best suited to you and your biology. 


If you're interested in reading more about where the points in this article came from, here is a list of our references for your convenience. Happy reading!


  1. Spiegel K, Leproult R, Van Cauter E (1999) Impact of sleep debt on metabolic and endocrine function. Lancet (London, England) 354: 1435-1439

  2. Spiegel K, Knutson K, Leproult R, Tasali E, Van Cauter E (2005) Sleep loss: a novel risk factor for insulin resistance and Type 2 diabetes. Journal of applied physiology (Bethesda, Md: 1985) 99: 2008-2019

  3. Gangwisch JE, Malaspina D, Boden-Albala B, Heymsfield SB (2005) Inadequate sleep as a risk factor for obesity: analyses of the NHANES I. Sleep 28: 1289-1296

  4. National Health and Medical Research Council (2015) Recommended number of serves for adults. Available from

  5. Michalsen A, Schlegel F, Rodenbeck A, et al. (2003) Effects of short-term modified fasting on sleep patterns and daytime vigilance in non-obese subjects: results of a pilot study. Annals of nutrition & metabolism 47: 194-200

  6. Rojdmark S, Rossner S, Wetterberg L (1992) Effect of short-term fasting on nocturnal melatonin secretion in obesity. Metabolism: clinical and experimental 41: 1106-1109

  7. Rojdmark S, Wetterberg L (1989) Short-term fasting inhibits the nocturnal melatonin secretion in healthy man. Clinical endocrinology 30: 451-457

  8. Brown R, Price RJ, King MG, Husband AJ (1990) Are antibiotic effects on sleep behavior in the rat due to modulation of gut bacteria? Physiology & Behavior 48: 561-565

  9. Everson CA, Toth LA (2000) Systemic bacterial invasion induced by sleep deprivation. American journal of physiology Regulatory, integrative and comparative physiology 278: R905-916

  10. Rupp TL, Acebo C, Carskadon MA (2007) Evening alcohol suppresses salivary melatonin in young adults. Chronobiology international 24: 463-470

  11. Rojdmark S, Wikner J, Adner N, Andersson DE, Wetterberg L (1993) Inhibition of melatonin secretion by ethanol in man. Metabolism: clinical and experimental 42: 1047-1051


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