A growing body of research shows that what we eat can affect how well we sleep, and how we sleep can affect the menu we choose. We spoke to nutritionist and naturopath Oliver Sanchez to learn which foods support better sleep and which might keep us up at night.

Deep sleep is an essential step in removing toxins and metabolic waste from the brain, helping to reduce inflammation and balance hormones. “So diet can affect sleep, and bad sleep can affect diet and further contribute to sleep problems, in a self-feeding cycle”, says Mr Sanchez. Studies consistently show that diets such as the Mediterranean diet, rich in vegetables, fruits, proteins, and healthy fats, are associated with better sleep quality.

Unfortunately, the glass of wine and sweet treat that often accompany us to the sofa may be doing more harm than good. “High intake of ultra-processed foods, saturated fats, and added sugars, and excessive alcohol consumption are linked to poorer sleep quality, nighttime awakenings, and reduced deep sleep,” says Mr Sanchez. High-fat or heavy meals can be challenging to digest, causing discomfort, while spicy or acidic foods may trigger indigestion or heartburn in susceptible individuals. As for sugary late-night snacks, these can spike blood sugar, leading to ‘restless awakening’. “Your blood sugar levels may crash, causing a sudden release of stress hormones, waking you up or disturbing your sleep with vivid dreams or nightmares.” says Mr Sanchez.

Caffeine, unsurprisingly, is one of the biggest culprits as it blocks adenosine, a neurotransmitter that promotes sleepiness. With a half-life of 6-8 hours, half of an individual’s caffeine intake can remain in their system, and may travel in their bloodstream up to 36 hours after ingestion. Mr Sanchez recommends that “most people should avoid caffeine at least 6 hours before bed, preferably none after, midday. Slow caffeine metabolisers may need a 10-12 hour gap”.

Caffeine has a similar molecular structure to adenosine, a chemical in the brain that ‘promotes rest and sleepiness’. As concentrations of caffeine dip, vast amounts of adenosine jump on cell receptors, suddenly causing you to feel tired. “This may also be accompanied by a sudden drop in blood sugar, provoking the production of stress hormones, making it harder to fall and stay asleep, even though the levels of adenosine have stabilised”, says Mr Sanchez. So if you do find that you’ve enjoyed a cup of coffee to curb the midday slump, a low-carb snack before bed could do the trick.

Generally, Mr Sanchez recommends finishing your main meal 2-3 hours before bedtime. However, a ‘small, sleep-friendly snack an hour before bed is acceptable for those feeling peckish’, including a handful of nuts or a small plain yoghurt. A glass of tart cherry juice can also help in topping up your body’s melatonin levels. For those who tend to wake in the night and struggle to fall back asleep, having a small bowl of almonds handy may be helpful. “Eating a couple of almonds or pumpkin seeds can help your body to lower the concentration of stress hormone in your bloodstream, allowing you to go back to sleep much quicker.”, says Mr Sanchez

And just as diet affects sleep, sleep affects diet, creating a ‘vicious circle’. Poor sleep destabilises hormone levels, particularly ghrelin, the hunger hormone, and leptin, the satiety hormone, driving cravings for high-energy, dopamine-boosting foods. “When you’re sleep-deprived, your brain’s reward system is more sensitive, making it harder to resist unhealthy snacks, particularly later in the day”, says Mr Sanchez. 

• Breakfast: Focus on protein and healthy fats to balance blood sugar and set the tone for the rest of the day. Avoid caffeine first thing, wait at least an hour after waking. Try porridge with nuts, a few banana slices and/or berries.
• Lunch: Avoid large, heavy meals as they will lead to a slump in energy and provoke cravings for caffeine or energy-dense foods. This is the worst time to have pizza or risotto. Instead, think grilled sockeye salmon with quinoa and steamed greens, or a bunless burger with potatoes or buckwheat and salad.  
• Dinner: Keep portions moderate. Try turkey or chickpea curry, spiced with different herbs, spices and black pepper instead of chillies, with brown rice and broccoli.

For individuals who suffer from persistent sleep disorders, some of the suggestions above may help; however, treatment often calls for a more comprehensive approach, including lifestyle changes and stress management. Mr Sanchez, who suffered from insomnia during his childhood, says: “People struggling to sleep, which fails to improve even with dietary and lifestyle changes, may have to work on their trauma or the cause of the anxiety, usually fueled by negative inner talk and rumination”. 

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