Most of us know that both nutrition and sleep are important pillars of good health. But what is perhaps less well known is just how closely the two are connected.
What and how we eat may influence our sleep, while how well we sleep can influence our hunger, food choices and how much we eat. It is a two-way relationship, and looking after one can help us to look after the other.
So, what can we learn from the science on eating well and sleeping well?
This is a surprisingly difficult question to study. Both our diets and our sleep are influenced by many other things – from physical activity and stress to working patterns, health conditions and our environment. This makes it difficult to say that a particular food or nutrient directly causes better or worse sleep. However, research increasingly suggests that overall diet quality matters.
One of the most studied dietary patterns is the Mediterranean diet. Despite the name, you certainly don’t have to live in the Mediterranean to eat this way! It is a predominantly plant-based way of eating, rich in vegetables, fruits, wholegrains, beans and pulses, nuts and seeds.
A large 2025 systematic review and meta-analysis, including 62 studies and more than 328,000 people, found that better sleep quality and sufficient sleep duration were associated with greater adherence to a Mediterranean dietary pattern (1).
Importantly, this doesn’t prove that eating a Mediterranean-style diet causes better sleep. The relationship is likely to work in both directions: people who eat well may be more likely to sleep well, while people who sleep well may also find it easier to eat well.
There has also been interest in individual nutrients such as magnesium, calcium and vitamin D. Although lower intakes or levels of some nutrients have been associated with poorer sleep, this doesn’t necessarily mean that taking supplements will improve it. Overall nutritional adequacy and dietary pattern are likely to be more important than chasing individual “sleep nutrients”.
This side of the relationship is particularly interesting and we now have evidence from controlled studies as well as observational research.
Sleep restriction has been shown to increase hunger and energy intake (a really important factor if you’re trying to manage your weight). A meta-analysis of randomised controlled trials found that sleep restriction increased subjective hunger and resulted in people consuming around 250 additional calories per day on average (2).
Researchers have also looked at what happens when people who routinely don’t get enough sleep are helped to sleep for longer.
In one randomised trial, 80 adults with overweight who usually slept for less than 6.5 hours per night were either given personalised support to extend their sleep or continued their usual sleep habits. Those in the sleep-extension group increased their sleep by around 1.2 hours per night and, despite receiving no instructions to change their diet, consumed around 270 fewer calories per day compared with the control group (3).
There are likely to be several reasons for this. Lack of sleep can influence appetite, reward responses to food and our decision-making around food. And there is the much more everyday reality of simply being tired.
Picture the scene: the alarm goes off after a broken night’s sleep and you drag yourself into a busy day. By lunchtime you’re ravenous and exhausted, so something quick and energy-dense (perhaps a pasty or a portion of chips) feels way more appealing than a colourful lunch. Later, you find yourself reaching for the biscuits to help you through the afternoon.
When we’re tired, planning meals, shopping, cooking and making considered food choices can simply feel harder.
So rather than thinking about sleep and nutrition as two separate health behaviours, it makes much more sense to think of them as interconnected.
This is one area where the evidence is considerably clearer. Caffeine works by blocking adenosine, a chemical that builds up in the brain during the day and contributes to our increasing drive to sleep.
A 2023 systematic review and meta-analysis found that caffeine reduced total sleep time by around 45 minutes, reduced sleep efficiency and deep sleep, and increased the time it took people to fall asleep and the amount of time they spent awake during the night (4).
And caffeine can hang around for much longer than we might realise. The same analysis estimated that a coffee containing around 107 mg of caffeine would need to be consumed approximately nine hours before bedtime to avoid reducing total sleep time.
That doesn’t mean everybody needs to stop drinking coffee at lunchtime, we metabolise caffeine differently and some people are much more sensitive to it than others. But if you are struggling with sleep, looking at how much caffeine you consume and how late in the day you consume it is a sensible place to start.
Remember that caffeine isn’t only found in coffee. Tea, energy drinks, cola and chocolate can contribute too. So take a look at your afternoon intake and consider what tweaks you could make (I personally switch to decaf or rooibos tea in the afternoon and evening and enjoy my chocolate after lunch instead of after dinner).
Alcohol can make us feel sleepy, which can create the impression that it helps us sleep. Unfortunately when it comes to alcohol, falling asleep quickly and getting good-quality sleep are not the same thing.
A 2025 systematic review and meta-analysis found that alcohol alters normal sleep architecture, including delaying and reducing REM sleep. Disruption to REM sleep was seen even following relatively low doses of alcohol and became progressively greater as alcohol intake increased (5).
Alcohol can also worsen snoring and sleep-disordered breathing. Research has linked alcohol consumption with an increased risk of obstructive sleep apnoea (6).
So while a nightcap might make you feel drowsy, alcohol shouldn’t be considered a sleep aid.
There is growing interest in chrononutrition – the relationship between when we eat, our body clock and our health.
Some research suggests that eating patterns and meal timing may be associated with sleep quality, but this is still an emerging area and we don’t yet have enough evidence to prescribe a perfect eating window for sleep (7). For most people, there is no need for a strict rule that you must stop eating at a particular time.
However, eating a very large meal immediately before lying down may make sleep uncomfortable, particularly if you experience indigestion or reflux. Leaving a little time (2-3 hours) between a large evening meal and bed can therefore be helpful, as it enables your body to focus on important sleep processes and not digesting your food from the day.
Unfortunately, there is no magic sleep food. You may have seen claims around foods such as tart cherries, kiwi fruit or foods naturally containing melatonin. There is some interesting research here, but it remains preliminary.
For example, a 2025 systematic review identified seven intervention studies investigating tart cherries and sleep. Some reported improvements in sleep duration, efficiency or time taken to fall asleep, but the studies differed considerably in their methods, doses and populations. The researchers concluded that the available evidence remains limited and heterogeneous (8).
So enjoy cherries and kiwi fruit if you like them, they’re nutritious foods, but I wouldn’t buy them specifically as a treatment for poor sleep.
Magnesium has become one of the most popular supplements marketed for sleep, but the claims have moved considerably faster than the evidence.
A 2026 systematic review examined 12 randomised controlled trials of oral magnesium for sleep, insomnia or poor sleep. Results were inconsistent and the certainty of the evidence was rated as low to very low. The researchers concluded that current evidence does not support routinely using magnesium supplements to treat insomnia (9).
Of course, magnesium itself is an essential mineral. Rather than automatically reaching for a supplement, include magnesium-rich foods regularly in your diet, such as nuts, seeds, beans, lentils, whole grains and green leafy vegetables.
Most adults need around 7–9 hours of sleep, although individual requirements vary (10). Rather than searching for one particular sleep food or supplement to get those hours under your belt, start with the foundations to support overall sleep quality (which can be just as or if not more important than total number of hours).
Aim for a varied and regular predominantly or exclusively plant-based diet rich in vegetables, fruits, beans and pulses, wholegrains, nuts and seeds. This gives your body the energy, protein, fibre, vitamins and minerals it needs without needing to micromanage individual “sleep nutrients”.
Regular movement and physical activity are important too, alongside exposure to daylight and a reasonably consistent sleep-wake routine.
Getting up at roughly the same time each day can help to anchor your body clock and initiate your sleep drive, and getting outside into natural light during the morning provides another strong signal that it is daytime.
Your bedroom environment matters too. A dark, quiet, comfortable room and a relaxing wind-down routine can make it easier to transition towards sleep.
And if sleep is a problem, take an honest look at caffeine and alcohol. These have much stronger evidence for affecting sleep than most of the foods and supplements marketed as sleep aids.
Sleep hygiene is useful for supporting healthy sleep, but chronic insomnia is not simply a failure to have the perfect bedtime routine.
If you regularly struggle to fall asleep, stay asleep or wake earlier than you would like, and this has persisted for three months or more and is affecting you during the day, it is worth seeking professional support.
Cognitive Behavioural Therapy for Insomnia (CBT-I) is the recommended first-line treatment for long-term insomnia and goes considerably further than simply advising people to avoid screens or drink less coffee (11,12). Similarly, symptoms such as loud snoring, gasping or pauses in breathing during sleep, significant daytime sleepiness or restless legs warrant further investigation.
There isn’t one perfect diet, food or supplement that will guarantee a good night’s sleep. Instead, the evidence points towards a much bigger picture: a nutritious, plant-rich dietary pattern, regular movement, sensible caffeine and alcohol habits and healthy sleep routines all form part of looking after ourselves. And importantly, the relationship works both ways.
Eating well may support healthy sleep, while sleeping well can make it easier to regulate our appetite, make nourishing food choices and have the energy to look after ourselves the following day.
Good nutrition supports good health. Good sleep supports good health. And increasingly, we’re learning that the two are very much connected.
Sleep tight x
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