What to Eat (and Avoid) for Better Sleep Tonight

The connection between diet and sleep is more direct than most people realise. Certain foods contain compounds that actively promote sleep, while others can sabotage your night before your head even hits the pillow. Here is what the research says about eating for better rest.

Foods That Promote Sleep

Tart cherries are one of the few natural food sources of melatonin, and studies have shown that tart cherry juice can increase sleep time by an average of 84 minutes. Kiwifruit, consumed one hour before bed, improved sleep onset and duration in a Taipei Medical University study — likely due to their high serotonin and antioxidant content. Fatty fish like salmon and mackerel provide vitamin D and omega-3 fatty acids, both of which support serotonin regulation and have been linked to improved deep sleep quality.

The Role of Tryptophan and Magnesium

Tryptophan is an amino acid that your body converts into serotonin and then melatonin. Foods rich in tryptophan include turkey, eggs, cheese, nuts, and seeds. However, tryptophan needs carbohydrates to cross the blood-brain barrier effectively, which is why a small carbohydrate-rich snack before bed — a banana, a handful of whole-grain crackers — can actually help. Magnesium, found in dark leafy greens, almonds, and dark chocolate, acts as a natural relaxant for the nervous system and has been shown to improve sleep quality in people with low magnesium levels.

What to Avoid After 2pm

Caffeine has a half-life of five to seven hours, meaning that half the caffeine from your 3pm coffee is still circulating at 8-10pm. Even if you fall asleep successfully, caffeine reduces deep sleep by as much as 20%. The safe cut-off for most people is early afternoon, though individual metabolism varies significantly. If you suspect caffeine is affecting your sleep, try eliminating it after noon for two weeks and observe the difference.

Alcohol: The Sleep Destroyer in Disguise

Alcohol is sedating, which many people mistake for sleep-promoting. In reality, alcohol fragments sleep architecture in multiple ways: it suppresses REM sleep, increases sleep-disordered breathing, triggers middle-of-the-night awakenings as your body metabolises it, and causes dehydration that leads to early-morning waking. Even moderate consumption — two drinks — has been shown to reduce sleep quality by nearly 40%. If you choose to drink, finishing at least three hours before bed minimises the disruption.

Meal Timing and Portion Size

Eating a large meal within two hours of bedtime forces your digestive system to work when it should be resting. This raises core body temperature, increases the risk of acid reflux, and can cause uncomfortable fullness that makes it difficult to relax. Conversely, going to bed hungry can also impair sleep, as low blood sugar triggers cortisol release. The ideal approach is a moderate dinner three to four hours before bed, with an optional small sleep-supportive snack — a handful of almonds, a small yoghurt, or a banana — if needed closer to bedtime.