It may be stating the obvious but one of the most effective ways to improve personal performance is to get a good night’s sleep. Everyone knows how much better they feel when they’re well rested and how much worse they feel - and perform - when they’ve slept poorly.
There is a now an abundance of research on the importance of good sleep and the impact it has on health. But did you know that it can even impact your prosperity? Gibson and Shrader (2014) discovered a correlation between sleep and income, estimating that a one-hour increase in average sleep increased wages by 16% (for the towns they studied in the US), equivalent to more than one year of schooling. The theory is that those who get enough sleep perform better, are more productive, and get better jobs.
Getting sufficient sleep and practising good sleep hygiene is therefore crucial if you want to lead a happy, healthy and prosperous life. You’ll probably already be familiar with the recommended tips. Having a regular sleep schedule, avoiding caffeine, and other stimulants before bed, avoiding alcohol, not exercising – or eating - too late, reducing light levels etc. But what makes the most difference?
As somebody who covets my sleep there is one factor I find to be most effective above all else. It is to leave at least a two to three hour gap between eating dinner and sleeping. It’s why when I run coaching and personal development retreats I recommend to my clients not to eat too late or to choose appropriate dishes off my menu if the evening is getting on.
The scientific evidence
After reviewing the scientific literature online I found the consensus to be that eating meals too close to bedtime is responsible for more nocturnal awakenings, poorer sleep quality, a reduction in sleep duration - including slightly less REM sleep (the mentally restorative stage of sleep), and poorer post-sleep restoration. Also “eating close to sleep predicts a higher total daily caloric intake in healthy adults, potentially increasing the risk of weight gain” according to Chung et al (2020). Conversely, earlier meal timing supports optimal sleep with all the associated benefits.
What my own data proves
The data I collect from my Fitbit fitness (and sleep) tracker shows what a difference eating late can make. On Sunday 21st August I ate a large meal at about 7.30pm (later than my usual time of 7pm) going heavy on the carbs and dessert, and accompanying it with a glass of wine. After washing up and taking a short walk I collapsed in front of the TV and continued indulging myself with a small bowl of nuts and chocolate nibbles (plus some more wine) not really finishing eating until 9.30pm and worse – idly grazing on some nuts and fruit at 10.30pm when I’d returned to the kitchen, and certainly wasn’t hungry. By the time my head hit the pillow it was 11.20pm and my heart was racing at 72 bpm from all the sugar I’d eaten, a rate equivalent to taking a brisk walk. Which you don’t want when you go to bed. It averaged 58 bpm the whole night. Unsurprisingly I had a very poor night’s sleep, earning a score of 74/100 on my Fitbit tracker.
The next day I fasted (I always fast Sunday to Tuesday evening), and had a pretty normal day, finishing the evening with a paddle with my sea kayaking club which meets on a Monday. I was pretty tired when I fell asleep at 10.50pm, my energy levels low from my exertions and from not having eaten. As a result I slept soundly, averaging a really low 45bpm average heartrate (what a contrast to the night before!) and earning a score of 88/100 on my Fitbit which is deemed good bordering excellent. I awoke feeling good and ready for the day ahead.
While this example may seem a little extreme because I went from splurging to fasting I consistently find that I sleep better whenever I eat dinner (my main and usually only meal of the day) at about 6.30pm or earlier ie 4 hours plus before I go to bed, or if my dinner is relatively light, even if I have a small snack close to bedtime (my Fitbit data corroborates this). On the other hand I always sleep worse whenever I leave less than 2 hours before dinner and turning in, and especially if I’ve indulged in sugary treats and/or alcohol. Though surprisingly I find a small amount of alcohol makes little difference especially when consumed with food as this helps mitigate alcohol’s disruption of the body’s ability to regulate temperature and bring core temperate down (essential to help you fall asleep). It’s the sugar that’s the main culprit when it comes to stealing my shuteye.
The result of failing to pull my eating window further from bedtime, and of late evening snacking, is that I feel worse and perform less well the next day. With a never-ending to-do list and less time left to do all the things I need - and wish - to do in my life (now that I’m over fifty) the cost of poor sleep is a price I always regret paying, not least because, like a speeding ticket, I could easily have avoided it with a little more self-discipline. It is probably my worst habit, one I’ve been take concerted steps to correct. I can’t really afford not to. If you’re similarly prone – can you?
What the solution is
The solution obviously is not to eat too late and to leave a 2 – 4 hour gap between eating dinner and sleeping as recommended by experts. An acceptable alternative would be to make lunch the main meal of the day so you only want a light dinner, soup or an omelette say, as is common on the continent, while still leaving a couple of hours between eating and bedtime. Personally I find two and a half hour gap to be enough. Always listen to your body and use a sleep log and/or data from a sleep tracker to help you work out what’s best for you. Better still consult an expert (see below).
This isn’t to say eating within one to two hours of sleeping is always bad. Indeed research suggests that if it’s late and your tummy is rumbling it can be prudent to eat something – preferably something light and easy to digest, rather than risk a disturbed sleep because you are hungry.
But on the whole eating a big meal within a couple of hours of going to sleep is a bad idea, as the research, and my own experience attests.
It’s common sense as much as anything else. Digesting food forces your body to perform a function it wants to have largely completed in order to move on to the next vital job of repairing and restoring your body back to health, a job it can only perform well during a prolonged period of settled and restorative sleep. It’s in our best interests to prepare the body accordingly.
What experts recommend:
Practice good sleep hygiene and remember your body needs time to digest in order for you to sleep well.
Try to leave 2 – 4 hours between eating a meal and bedtime, veering towards 4 hours if your meal is high in calories with large amounts of fat or carbohydrate.
Avoid consuming spicy foods, foods high in fat, such as fried foods, ultra processed food, full-fat dairy products, acidic foods, caffeine-containing food and drink, including chocolate, coffee, and tea, and alcohol in those precious hours preceding bedtime as they’re likely to disrupt your sleep as well as your ability to fall asleep.
If managing blood sugar, or you are simply hungry, having a snack near bedtime is probably a good thing depending on the individual.
If you have decided to eat close to bedtime consider foods which contain nutrients and anti-oxidants (such as the sleep inducing hormone melatonin) conducive to sleep such as tart cherry juice, kiwis, walnuts, almonds, and other nuts, and milk. Check out https://www.sleepfoundation.org/ for more information.
What is your own experience? I’d be fascinated to learn. Why not leave a comment?
At Headspace Coaching I care passionately about giving my coaching and 'Life Re-creation' retreat clients the best possible experience, which includes practising good sleep hygiene on top of providing the most comfortable sleeping environment so you get the most from your stay. Check out my website to learn more about what I offer.
Are you an individual or group wanting to improve your relationship with sleep? My friend Kellie Gilmour, 'The Sleep Mentor', may be able to help. Check out her website for more info.