Could we lose weight just by getting more sleep?
Scientists based at King's College London in the United Kingdom have recently conducted a pilot study investigating sleep and diet. Their findings might be good news for those of us who feel tired and chubby at the moment.
Sleep is a strange beast. Most of us know that we feel awful if we don't get enough, yet hardly any of us manage the recommended 7-ish hours that we need.
In actual fact, according to the Centers for Disease Control and Prevention (CDC), 1 in 3 Americans don't get the right amount of shut-eye.
This is quite a worrying statistic, as sleep — or a lack thereof — is now considered to be a risk factor for obesity and cardiometabolic conditions, such as impaired glucose tolerance and high blood pressure.
If lack of sleep can have such a major impact, it seems sensible to search for ways of extending sleep in individuals who might be at risk.
Dr. Wendy Hall, from the Department of Nutritional Sciences at King's College London, and team recently completed a pilot study in which they tested whether or not a simple intervention could increase sleep duration in a group of adults.
Their results are published today in the American Journal of Clinical Nutrition.
In all, 21 healthy short-sleepers undertook a 45-minute sleep consultation. During this session, the sleep extension group were given at least four helpful hints to lengthen their sleep time, including information about reducing caffeine intake — having a coffee just before bedtime makes it harder to drop off (who knew?) — and setting up relaxing routines, such as a warm bath and some Kenny G.
For the next 7 days, the participants kept sleep diaries. They also wore a motion sensor that could detect exactly how long participants slept, and how long they spent in bed before falling asleep.
Alongside the researchers' efforts to extend sleep duration, they also monitored nutritional intake throughout the study period.
Overall, 86 percent of the sleep extension group increased their time spent in bed, and around half increased their sleep duration (by 52–90 minutes). Three members of the group hit the weekly recommended average of 7–9 hours of sleep per night.
However, the researchers believe that the extra sleep that the participants got might not have been of particularly great quality. They conclude that it might take a little more time to get into a new sleep routine; Kenny G can only do so much.
Intriguing dietary changes
OK, so I know you're desperate to read about the dietary aspect of the study, and the diet diaries threw out some interesting findings. For example, the individuals who did manage to attain an extended sleep pattern reported eating 10 fewer grams of free sugars, as well as fewer carbohydrates, per day.
"The fact that extending sleep led to a reduction in intake of free sugars, by which we mean the sugars that are added to foods by manufacturers or in cooking at home as well as sugars in honey, syrups, and fruit juice, suggests that a simple change in lifestyle may really help people to consume healthier diets."
Dr. Wendy Hall
But before we all get too excited and rush out to buy new mattresses, it's important to note that the study is just a pilot. It involved 21 people, only 18 of whom extended their time in bed, and it took just over 1 week to complete.
Having said that, because sleep is a known risk factor for many diseases, it's important to build on these limited foundations. Further research needs to identify whether or not it is possible to make meaningful changes to sleep habits in this way.
As lead researcher Haya Al Khatib says, "We have shown that sleep habits can be changed with relative ease in healthy adults using a personalized approach."
"Our results," she continues, "also suggest that increasing time in bed for an hour or so longer may lead to healthier food choices. This further strengthens the link between short sleep and poorer-quality diets that has already been observed by previous studies."
They plan to extend their foray into sleep modification and diet. Al Khatib continues, "We hope to investigate this finding further with longer-term studies examining nutrient intake and continued adherence to sleep extension behaviors in more detail [...]."
So, for now, we should take the findings with a pinch of salt; a lot more work will be needed to firm up the conclusions. That being said, it's now well-established that as a nation, we need more sleep — so you may as well give it a try.
Just to throw one final cat among the sleep-deprived pigeons, there is also some evidence that sleeping for too long increases mortality risk. As ever, moderation is key. Not too much, not too little.
On a personal note, I have 1-year-old twins, so the chances of me ever getting enough sleep are incredibly slim — unlike my waistline.