How can nutrition impact sleep?

October 4th, 2019

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By Rhiannon Lambert, Registered Nutritionist

We all know that a bad night’s sleep can make us feel less than our best, from decreasing our mood, reducing our concentration and making us feel less alert.1 There is no doubt that insufficient sleep can impact us in the short-term, but did you know long-term sleep deprivation has been linked to increased risk of diabetes, heart disease and strokes?But, how much of a role does nutrition really have on our sleep and how can we eat better to sleep better?

Think about the quality of your diet

Whilst there is no such thing as good or bad food, research does show that individuals who have a balanced and varied diet are more likely to sleep well. For each meal, make sure to get a varied plate, focusing on protein, carbohydrates, vegetables and healthy fats. Deficiencies, in particular vitamins and minerals such as iron2 and Vitamin B12, can cause fatigue and tiredness and may cause problems for your sleep. High iron foods include red meat and good plant based options are legumes and pulses, while for Vitamin B12; meat, salmon, dairy and eggs are all great sources, however if you are vegan then the only reliable sources are fortified food and supplements.3

Carbohydrates may help

Carbohydrates can make you feel incredibly tired, especially after a large meal. The reason for this is that carbohydrates can help produce tryptophan amino acids that are found in the brain, which in turn may make us feel sleepy.4 Tryptophan actually converts into serotonin and then turns into melatonin, which helps regulate our circadian rhythm. As a result of the role melatonin plays with our sleep cycle, it could be a reason for feeling tired after a meal high in carbohydrates. In order to get the best result, research has suggested that you should eat carbohydrates with your meal around four hours prior to going to bed. 

Cut down on caffeine

Caffeine can stay in your body for up to 14 hours, meaning it can seriously disrupt your circadian rhythm. It not only increases the time it takes you to fall asleep, but it also reduces the quality of your sleep as a whole. If you find yourself struggling to fall asleep at night, your afternoon and evening coffees could be to blame. It is important to remember that caffeine is also in other products other than coffee, including various teas, cola drinks and chocolate. Try to be aware of how much you are consuming and cut down on the quantities you’re having if you’re struggling to sleep at night.5

Drinking can make it worse

Often in the evenings, people want to wind down and have a drink. This is seen by many as an aid to getting to sleep quickly, as its sedative effect makes individuals feel as if they are falling asleep faster.6 However, research suggests that after a drink, you spend less time in REM sleep (Rapid Eye Movement sleep), and it is this sleep that makes us feel more rested.7,8 If you want to improve the quality and quantity of your sleep, consider cutting out or reducing the amount you drink early in the week.

If you’re really having trouble sleeping and struggling with solutions the best thing you can do is to contact your GP for advice.

About Rhiannon Lambert

Rhiannon Lambert is a Registered Nutritionist, founder of Rhitrition, London's leading private nutrition clinic, bestselling author of Re-Nourish: A Simple Way To Eat Well and podcast host of Food For Thought.

Her qualified approach to nutrition and total dedication to sharing evidence-based advice has seen Rhiannon work with some of the world’s most influential people.  

For more information, please visit and follow @Rhitrition on Instagram, Twitter, Facebook and YouTube.