Tweaking your night-time routines may be an unexpected way to reduce your food intake, with a beneficial side-effect of being more rested.
Studies where people’s sleep is deliberately reduced suggest that we tend to eat more when we sleep less. Sleep reduction in healthy individuals is associated with an increased energy intake of about 300 Calories a day.
Explanations for why this might be include increased hunger, alterations in appetite-regulating hormones, changes in brain regions related to reward-seeking or simply being around food for longer.
In the real world
As these studies were conducted in artificial laboratory conditions, researchers at the University of Chicago wanted to see what happens if you help people who currently get less than 6.5 hours a night, to extend their time asleep in the more normal setting of their own home.
Dr Esra Tasali and colleagues1 looked at the effect of sleep extension on energy intake in 80 adults who were overweight, in their usual home environment. They compared people who had individualised sleep advice (“sleep intervention”) with those who had a chat with an experimenter but didn’t get the sleep-improvement tips (“control group”).
The timescale of the study started with 2 weeks of monitoring sleep (using wrist-worn tech) and then either getting the sleep advice or having the general chat. There were two further weeks of sleep monitoring to see what, if anything, changed.
What did they measure?
The researchers could tell how long people had actually slept from the wrist-watch tech they wore. They were able to calculate energy intake and expenditure using a mix of physical measurements – which means they weren’t reliant on food diaries, which can be inaccurate.
Even in two weeks, things changed
What they found was that compared with the control group,
- the intervention group significantly extended their total sleep time by approximately 2 hours per night
- the sleep intervention significantly reduced their daily energy intake by approximately 270 Calories compared with the control
- total energy expenditure did not significantly differ between the sleep extension and control groups.
- participants in the sleep extension group had a statistically significant reduction in weight compared with those in the control group
The findings suggest that improving and maintaining adequate time asleep could help reduce your weight, over and above any changes you’re making to how or what you eat.
Two hundred and seventy calories a day
Reducing daily energy intake by 270 kcal, is quite something if it becomes a habit. Particularly if that habit change brings other benefits along with it.
Compared with the control group, the sleep intervention group reported more daytime energy, alertness and better mood.
A bit of a puzzle
It must be said that for some reason the control group, who simply carried on as normal, increased their energy intake over the course of the study and it’s not clear why that might have happened. No doubt there will be more research to follow.
The study was only short (4 weeks) so a key question is what would happen over a longer time.
Might you be able to improve your sleep?
If this study has whetted your appetite for getting more sleep yourself, there are lots of good resources out there. My favourite three are…
- Sleepio is 6-week digital online course, developed by Professor Colin Espie. One of the key features is increasing sleep quality and reducing the amount of time you spend in bed lying awake. It has loads of tips on different aspects of improving sleep, drawing on Cognitive Behavioural Therapy for insomnia. There are places in the UK where Sleepio is available for free, and in the USA, Sleepio programmes are covered by some insurers or employers. I did the Sleepio programme myself a few years ago and loved its practical, guided process with lovely animations of the Professor and his dog! I can’t see what the cost is currently if you’re not eligible to get it for free, so you would need to check this out via the website or the app.
- My colleague Dr Ashish Bhatia, A Bristol GP and Lecturer at Bristol University Medical School, has a particular interest in sleep2. He runs groups and works with individuals to improve health and wellbeing, and his youtube channel is full of helpful nuggets of information and wisdom. Here is his youtube talk on some simple steps that can help us improve the amount and quality of our sleep.
- My third recommendation is Mark Grant’s Sleep Restore app. Mark is a Clinical Psychologist in Australia and from his original work on managing chronic pain, he has developed some lovely apps which are cheap and really easy to use. His Sleep Restore app is free and includes specific information about sleep problems which occur as part of PTSD (Post-Traumatic Stress Disorder) or as a result of emotional neglect or abuse. He delves into particular difficulties with sleep that are associated with psychological trauma, but the App is great for anyone. There are different tracks for falling asleep and for getting back to sleep after waking.
I hope you like these resources – they all have richness and depth to them, and the potential to gently and powerfully change the quality and amount of shut-eye you enjoy.
- Tasali et al (2022) Effect of Sleep Extension on Objectively Assessed Energy Intake Among Adults With Overweight in Real-life Settings: A Randomized Clinical Trial JAMAIntern Med. 2022;182(4):365-374. doi:1001/jamainternmed.2021.8098
- Bhatia, A. Humble Sleep
Photo by Beazy for Unsplash