A nutritionist wants you to consider not just when you eat, but what you eat if you can’t sleep at night

We’ve all been there: lying awake at 2am with a racing mind, wondering why you can’t sleep.

While the odd restless night is usually nothing to worry about, if you’re struggling to fall asleep regularly—or waking up feeling even more exhausted—it could be a sign that something in your daily routine is to blame.

And that something could be your diet, according to Sophie Bertrand, resident nutritionist for Abbott’s Lingo—an everyday wearable that tracks your glucose around the clock.

She explains that those sleepless nights could be down to what you eat and when you eat it.

“Aim to finish your last meal two to three hours before sleep as eating too close to bedtime may cause a spike in glucose levels and insulin,” says Bertrand.

“This inhibits the release of growth hormones and can signal wakefulness to the body.”

And while many of us may already know that eating too close to bedtime is a no-go, timing isn’t all that matters, what you eat before bed matters too, as does what you eat throughout the day.

Here, Bertrand shares three nutrition factors that could be impacting your sleep—and what you can do about them.

1. Consider what you eat in the evening

Bertrand advises prioritising meals with a low Glycaemic Index (GI) at dinner time. These are foods that cause a slow and gradual rise in blood sugar levels, rather than quick spikes.

They are often recommended to people living with diabetes or as a weight-management strategy. Foods are scored on a GI scale of 1-100, and anything 55 or below is considered low GI.

“Prioritise meals with a low GI—with high fiber, whole grains and vegetables alongside protein,” Bertrand says.

“Avoid sugary drinks and fruit, and instead opt for complex carbohydrates allowing for a slow, steady release of energy to help support deep sleep.”

Examples of low GI foods include:

• Lentils, chickpeas and beans
• Wild rice, brown rice and quinoa
• Broccoli, courgette and leafy greens
• Chicken, tofu, fish or eggs

If you are someone who wears a continuous glucose monitor device during the night, it will show spikes or dips when you’re sleeping, which could be a sign that your body is struggling to regulate glucose levels.

“Glucose spikes at night can disrupt sleep quality, leading to restlessness and poor REM sleep,” says Bertrand.

“On the other hand, low glucose levels (hypoglycaemia) during the night can trigger a stress hormone response, disrupt restorative sleep and lead to daytime tiredness and irregular sleep patterns if it occurs regularly.”

If you don’t have a monitor, use notes to track your sleep, what you’re eating and when you’re eating it to work out if there are any particular foods and mealtimes that are affecting your sleep.

2. Incorporate magnesium-rich foods

If you’re struggling to sleep, you’ve probably been recommended magnesium supplements at some point—but did you know you can get magnesium from your diet too?

“Magnesium helps regulate the neurotransmitters that calm the nervous system,” Bertrand explains.

Adding magnesium-dense foods like pumpkin seeds, spinach, or almonds into your diet can promote relaxation in the mind and body, and lower cortisol levels which can disrupt sleep.

“Magnesium can help reduce that tired but wired feeling that many people experience when they can’t sleep,” says Bertrand.

3. Consider your nutrition throughout the day

Ok, so you’ve ditched the high GI foods at dinnertime and made sure to eat two to three hours before bed. What about the rest of the day? Well, it’s just as important according to Bertrand.

“Sleep quality starts at breakfast. If you’re experiencing many glucose spikes and crashes during the day, your baseline stress hormones remain elevated,” she tells Fit&Well.

High cortisol levels impact the body’s ability to produce melatonin (our sleep hormone) and impact both the length and quality of our sleep.

If you’re a caffeine fiend, Bertrand suggests learning what your tolerance is.

“Caffeine blocks adenosine, the chemical that helps your body feel sleepy, making it harder to fall into deep, restorative sleep because it stays in your system for hours,” she explains.

Everyone is different, for some having a coffee in the afternoon doesn’t have much effect. For others, caffeine after midday can impact sleep and recovery.

If you find yourself struggling to sleep, try having your last coffee earlier in the day and see how it impacts you.