Food and Sleep: Is There Any Connection?

Sleep is something everyone covets, but most of us don’t get enough of it.

The majority of us need around 7-8 hours a night, depending of our age, and as we approach midlife, it seems like our lack of quality sleep really catches up with us. 

There’s some legitimate reasons for that:

We’re so busy, it’s hard to turn our brain ‘off’ for sleep. 

Shifting hormones can keep us lying awake for no apparent reason, or wake us up sweating (and freezing).

We revenge-scroll late into the night to make up for the time we didn’t get to ourselves during the day.

If you’re anything like me, you also have a partner who snores and a dog that walks around all night. I swear, so annoying. They’re lucky they’re both cute.

Sleep is important for so much of what we do in life. Without adequate sleep, we’re more likely to overeat, our executive function suffers, our mood can be negatively affected, and we’re more likely to develop chronic disease.

Whatever the reason for our poor sleep, some diet changes and supplements may help. As a dietitian, I always recommend to my clients to work on sleep hygiene first – putting devices away at least an hour before bedtime, keeping the room on the quiet, cool, and dark side, not eating large, high-fat meals before sleep, and managing stress. The power of setting boundaries and saying ‘no’ to non-mandatory obligations is magical, too – let’s not forget about that. Stuffing your calendar with things you feel bad about turning down is a major stress-builder.

Read my post about the importance of setting boundaries and how to do it, here.

Once sleep hygiene is optimized, if you’re still having trouble getting your ZZZZ’s, I recommend trying some dietary interventions. If you decide to do that, it’s best to do it one at a time, each for a few weeks, to give you an idea of exactly what works, and what doesn’t. 

I am not a nutrition and sleep expert, so for this post, I consulted Karman Meyer, registered dietitian, speaker and author of Eat to Sleep: What to Eat and When to Eat it for a Good Night’s Sleep. 

Karman knows what she’s talking about regarding sleep and food, so here’s what she recommends.

Sleep and food: be a pencil, not an eraser.

My favorite thing to tell people is to add food to their diets, not take it away. And sure, we know that caffeine and alcohol can disrupt sleep. But adding magnesium-rich foods to your diet during the day can have a positive impact on sleep. 

Magnesium is a mineral that relaxes our muscles, regulates blood pressure, and keeps bones strong, among other things. We need 310-320 mg (women) to 400-410mg (men) of magnesium a day, and some sources say 50-75% of adults don’t get enough, so assessing whether you’re one of those people, is a great place to start your sleep-improvement journey. I talk about magnesium supplements separately, so keep reading!

Foods that are high in magnesium include leafy greens, dairy products, pumpkin seeds (a serving contains 37% of our recommended daily amount!), beans, and nuts. 

Trytophan, that amino acid that everyone says makes us sleepy after the Thanksgiving turkey, may also help. (Side note: it’s likely the overeating, not the tryptophan, that causes our food coma). Foods high in tryptophan include dairy products, legumes, and meats, but research is mixed on whether or not there’s an actual solid connection between them and improved sleep.

Carbohydrate helps the uptake of tryptophan by the brain. The tryptophan is then used to produce serotonin, some of which is converted to melatonin, which promotes sleep.

Who said sleep wasn’t complicated? Graphic from https://pubmed.ncbi.nlm.nih.gov/33942088/

And just in case you thought that carbs are the sure-fire way to a good night’s sleep, the totality of the research is not as clear.

Some research indicates that sugary foods, high-glycemic carbs, and refined carbs may be linked to poor sleep. 

This 2020 study suggests that eating a meal that’s rich in carbohydrate may impact insulin levels and disrupt sleep. 

Some studies suggest that while carbs, protein, and fat all affect sleep, that effect varies between individuals and the benefits or drawbacks can’t be drilled down to one single macronutrient. 

This 2023 study concluded that a diet that provides too much energy – specifically from carbs and fats – negatively impacts sleep. It also found that a diet that’s balanced and rich in micronutrients, has a positive impact on sleep. 

I know, this is all very mixed up. Research can be that way, because each study is different, done with different populations, different outcome measures, and different doses. The best way to deal with this is to look for a pattern. 

Here it is: all signs point to a balanced, varied diet being helpful for sleep.

Melatonin, but make it from food.

Melatonin supplements are what a lot of people reach for when they can’t sleep, but they may not be your best bet. 

Melatonin is a hormone that’s secreted by the pineal gland in our brain. It helps regulate our internal body clock, and although melatonin supplements can be effective for sleep, they do have their downsides.

Supplements overall are not regulated by the FDA, and dosages on the bottle may not reflect what’s actually in the product. Long-term use of melatonin can have side effects, including dizziness, daytime drowsiness, irritability, and feelings of depression.

Anecdotally, my experience with taking melatonin for sleep was a real eye-opener (no pun intended). After a few weeks of taking it every night, I began to feel very depressed. It took me a few days to realize that it was actually the melatonin supplements that were having this very scary effect on me. I stopped taking them immediately, and the depression went away. I personally will never take melatonin again.

You can always try to get melatonin from food sources. Tart cherry juice, almonds, pistachios, and eggs contain melatonin. Just as an aside, research tells us that light is more effective for melatonin production than food. It’s not nutrition-related, but make sure you get daylight on your face every day. 

Food and sleep, hormone edition

If you’re in perimenopause or early menopause and you find yourself lying awake at night for no particular reason, it may be your hormones. 

Hot flashes and night sweats can also be disruptive to your ability to fall asleep and stay asleep. 

Hormones are intimately linked to sleep quality and sleep disturbances. Progesterone has a hypnotic effect and promotes regular sleep cycles. When our progesterone levels fluctuate and dip in midlife, it can cause insomnia. Some studies have found that low estrogen levels are associated with impaired sleep quality and ability to stay asleep, but others have found no connection. 

The research has consistently been mixed around the benefits of using soy products for menopausal symptoms. Increasing your soy intake definitely can’t hurt (I’m a huge fan of soy foods in general), and no – it does not increase the risk for breast cancer. 

Cutting down alcohol, caffeine, and spicy foods may prevent hot flashes, which can be extremely disruptive to sleep. 

There’s also some research on valerian, a plant supplement which may help with sleep disturbances. 

Menopausal Hormone Therapy may also help alleviate sleep issues in menopause. Whether to start MHT is a very personal decision that should be discussed with your healthcare professional.

What is chrononutrition?

I can’t write about sleep and nutrition without mentioning meal timing and the effect it can have on our metabolic health. I wrote in a lot of detail about chrononutrition here, but the main idea is that when we eat can impact our blood sugar and blood lipid levels and overall metabolic health.

This incredible 2021 study found that eating the majority of your calories in the latter part of the day is associated with higher weight and higher risk for chronic disease.

In short, we used to believe that eating however much food late at night was fine. It’s fine to have a protein-rich snack before bed, but try to consume the majority of your food earlier on.

Supplements for sleep might help

Just like magnesium-containing foods, magnesium supplements may help with sleep. Magnesium supplements come in several forms – magnesium citrate and magnesium glycerinate are two of the most recommended forms for sleep in particular.

The issue? The evidence around magnesium promoting sleep is just not all that good.

The tolerable upper limit for magnesium supplements is 350mg. Taking more than that can give you diarrhea (that will really impact your sleep!)

In recent studies, tryptophan supplementation in doses of around 1g has been shown to be effective for sleep.

L-theanine is another supplement that’s marketed as a sleep aid. L-theanine is an amino acid that’s found in green and black teas, and some small studies (and here) have found a positive association between this supplement, stress, and sleep. More research is needed.

GABA (gamma amino butyric acid) is often included in supplements that claim to be sleep-promoting. This neurotransmitter can be found in foods like tomatoes, soy, and tea, and was the subject of this 2022 study around GABA and sleep. The study found a small positive outcome in the time to fall asleep, staying asleep, and insomnia, but there were major limitations as well. The most important limitation was that this study was actually presented as a letter to the editor of a journal, and not peer reviewed. It was also sponsored by a supplement company.

5-HTP is often sold as a sleep aid, and included in sleep-promoting supplements. However, the research behind 5-HTP for sleep is not convincing. 

CBD is the new kid on the block, and some research has found it to be effective for sleep via a reduction in anxiety levels. However, this 2024 study found the opposite. If CBD works for you, by all means, use it! 

It’s important, as with all supplements, to understand what the effective dose is, and to know if there are any interactions with your health status or medications you’re taking. Please buy any supplements from trusted sources. 

Sleep can be elusive, especially during certain phases in our lives. Diet and supplements may help, but remember to pair them with good sleep hygiene. If you still have trouble sleeping, please see a doctor. 

And buy Karman’s book! Here’s the link again:  Eat to Sleep: What to Eat and When to Eat it for a Good Night’s Sleep.