What we eat doesn’t just impact our health – it affects our sleep, too…

How much we sleep – and how good the quality of that sleep is – has a big impact on us, physically and mentally. We already know that what we eat, when we eat, and how much we eat and drink can impact the quality of our sleep. But what should we be eating to get the best night’s sleep possible? 

A new study has looked at how what we eat each day affects how our bodies function while sleeping at night. Research suggests that eating more fibre could be the key to sleeping more deeply, while having a wider variety of fruit, veg, and nuts in your diet could help you to fall asleep more quickly. 

Previous studies have suggested that fibre could help improve your sleep and that not getting enough fibre is linked to sleeping for shorter periods of time. Ensuring you eat foods high in fibre can help you to sleep more deeply as fibre helps stabilise blood sugar and supports a healthy gut microbiome. Many previous studies have relied primarily on people remembering their diet in surveys, sometimes weeks or months later. In other studies, when sleep has been measured, it is usually using movement trackers, which aren’t able to tell the difference between different phases of sleep – something that is important to gauge sleep quality. This latest study analyses sleep and dietary data collected from more than 3,500 adults, looking at dietary and sleep factors that have not been explored in one study before.

Participants logged what they ate using a mobile app while eating or shortly afterwards, for two days in a row. Each night, they wore a device to measure sleep, which tracked snoring, heart rate, breathing rate, and blood oxygen levels. Using these measurements, researchers were able to estimate how long each person spent in light sleep, deeper, restorative sleep, and REM sleep (rapid eye movement sleep, where we dream more vividly). 

Researchers predicted how 25 different dietary factors would affect participants' sleep, accounting for their age, sex, caffeine intake, and their dietary and sleep data from the previous day. Researchers found that those who ate more fibre than the average for the group were more likely to get a better night’s sleep than those with a below-average fibre intake. Additionally, they found that those who consumed more than the average amount of fibre had a slightly lower heart rate at night, suggesting they had entered a deeper sleep state where their bodies could rest and repair. 

Participants who ate more than five types of plant-based foods a day were found to fall asleep slightly faster and had a lower heart rate during sleep than those who ate fewer varieties of plant-based foods. Further research is still needed to confirm findings, but this latest research adds to a growing body of evidence that suggests fibre – and a variety of plant-based foods – could play an important role in how much – and how well – we sleep. 

Foods for a better night’s sleep

While further research may be ongoing, existing research suggests that there are still small changes you can make to your diet and foods to help promote a better night’s sleep. Melatonin-rich foods like kiwi, nuts, oily fish, dairy, and tart cherries can help improve your total sleep time and efficiency. Melatonin helps regulate your internal body clock, meaning foods rich in melatonin can gently help to reinforce these nighttime signals and get ready for a relaxing night’s sleep. 

Tryptophan-rich foods (fatty fish, nuts, seeds, dairy, and poultry) can be seen as the building blocks to help your brain switch into sleep mode. Tryptophan-rich foods provide the materials your brain needs to produce serotonin and melatonin. Higher serotonin levels can help promote feelings of calm and emotional stability, while having more tryptophan may help support melatonin production. 

Leafy greens, sweet potatoes, bananas, and avocados are a mixture of foods rich in magnesium and potassium. These can help your body to relax. Magnesium can help to regulate your nervous system, reduce muscle tension, and may affect your cortisol levels (helping lower your stress levels). Potassium can help prevent nighttime muscle cramping, reduce how many times you wake up during the night, and help you to be more relaxed, making it easier to fall – and stay – in deeper sleep stages. 

While adding a little more fibre to your diet or variety to your plate may start to have a positive impact, lasting improvements to sleep – and our overall health – may be more likely to come from looking at our diets as a whole. Everyone’s body responds differently to certain foods, eating patterns, and nutrient levels. Factors like stress, hormones, gut health, and underlying health conditions can all play a significant role in how well we sleep. 

If you’re struggling with restless nights or ongoing fatigue, it could be a case of doing a little more than increasing your fibre intake. Working with a registered nutritional professional can help you to better understand what your body may be missing, creating a personalised plan to help support both your sleep and overall health. Sometimes, better rest really can start at the dinner table – with a little help and guidance along the way.