There have been various studies examining the relationship of sleep, health and body weight in recent years. Here we look at 3 pieces of research which link sleep and weight. This follows on from the There appears to be a complex relationship between sleep, hunger, hormones and metabolism that has a direct effect on health.
Sleeping More Helps You To Lose Weight
Another study revealed that there is a a link between sleep duration and weight. A paper in the Annals of Internal Medicine explains how lack of sleep can cause people to gain weight and why dieters sometimes fail to lose weight. The research was carried out by scientists from the University of Chicago and University of Wisconsin.
There has been a known connection between sleep and weight loss for many years but it was always assumed that the reason was because over-tired people tend to snack more and make poorer food choices throughout the morning. However, the researchers have determined that the real reason why reduced sleep leads to weight gain is due to changes in the basal metabolic rate (metabolism) as we become more tired. Tiredness literally slows us down and stops our body from burning fat.
The research examined 10 middle-aged, overweight subjects with an average body mass index of 27.4, which is mid way between being overweight and obese. The subjects were then restricted to either 5.5 hours or 8.5 hours of sleep per night on two separate occasions.
55% Less Fat Lost in the Tired Group
Examinations revealed that when overweight people only got 5.5 hours of sleep a night they lost 55% less fat while dieting that those that received a full nights sleep.
The hormone that varied most was ghrelin which is a hormone produced inside the stomach and pancreas that stimulates hunger.
It was concluded that the amount of sleep has a direct influence on how our bodies burn fat and use energy when dieting. Simply not getting enough sleep could be enough to prevent you from losing weight.
The researchers admitted that the size of the trial was rather limited and ideally they would be able to carry our more research into this area of weight loss to support this theory. The research was funded by the National Institutes of Health.
So if you are trying to lose weight, you really do need to just sleep on it, and also reduce calories, eat low GI carbohydrates, exercise more frequently and more intensively!
Sleep has been found to have other health benefits too, it is certainly not just about losing weight. Other studies have shown that a lack of sleep can cause an increased risk of heart disease and other problems.
Sleep in the Dark to Lose Weight
Researchers have discovered that sleeping in a light room, even just a dimly lit room, may be linked to weight gain, even if diet and activity levels remain that same. It seems that hormones play a vital role in determining if we lose weight or gain weight. This research also helps to reinforce the theory that lack of sleep causes weight gain – people who do not get enough sleep are exposed to more light.
Increased BMI When Sleeping Under Dim Lights
The latest research was carried out on mice. A set of mice were exposed to dim light at night for a period of 8 weeks. This group of mice gained weight (measured in BMI) at a rate 50% faster than the mice that slept in the total dark.
“Although there were no differences in activity levels or daily consumption of food, the mice that lived with light at night were getting fatter than the others,” Laura Fonken, lead researcher at Ohio State University
However, it is not as clear as this. In one study mice that slept in light conditions but had their food provided during normal hours did not gain weight. It seems that the light itself increases hunger in mice and when exposed to lighter conditions mice want to eat more.
“To promote optimal adaptive functioning, the circadian clock prepares individuals for predictable events such as food availability and sleep, and disruption of clock function causes circadian and metabolic disturbances.”
The mice which slept under dim lights showed an increase accumulation of epididymal fat and impaired glucose tolerance, both of which are an indicator of pre-diabetes.
This suggests that people who sleep in light conditions may also be more likely to gain weight and develop type 2 diabetes.
Late Nights, Computers and Television
The researchers also suggested that one of the reasons for rising levels of obesity, especially in children, is that people are staying up later at night and using televisions and computers more. This means that we are exposed to a lot more light than we required and this may affect appetite, triggering the brain to demand food for longer periods which results in late night snacks.
Although this research has not been proved to be relevant to humans there is a lot of circumstantial evidence that suggests that this may be true for humans too.
Studies have shown that people who do not sleep enough put on more weight. Also athletes and bodybuilders also agree that more sleep helps to keep fat levels down. Therefore if you want to learn how to lose weight then two simple changes you can make to your lifestyle are:
- Go to bed earlier and limit computer use and television before bed
- Sleep in total darkness. Put up thicker curtains and turn those night lights off.
Also you should encourage children to sleep in the dark for the same reason. Many children like a night light for comfort, but not only do these cause disrupted sleep they may also be contributing to weight gain. So go to bed early, say good night and turn out the light. You will also save money.
If You Cannot Work Out How To Lose Weight, Sleep On It
Research from the Birmingham Heartlands Hospital has provided further evidence that sleep helps us to lose weight. Their research supports the theory that a lack of sleep may be the root cause of weight gain for many people.
“We discovered that people who sleep for significantly less than seven hours a night often end up being obese.” Dr Shahrad Taheri, Birmingham Heartlands Hospital, UK.
In a study, subjects that slept for less that 4 hours a night would consume up to an additional 900 kcal per day in snacks alone. Sleep deprivation leads to some serious snacking.
People are getting on average 2 hours sleep per night less than they did 50 years ago. During the 1950’s people slept for 9 hours per night. In these days there was no late night television at all, no Internet, and very little radio. There really was not much to do at night, so people would usually be tucked up in bed by 10pm every night. Nowadays people are watching television late into the night mid-week, and checking emails and social networking sites before bed, adding hours to their evening.
“We suspect sleep loss may not only hasten the onset, but could also increase the severity of ailments such as diabetes, hypertension, obesity and memory loss.” Eve Van Cauter, lead researcher.
As we have mentioned before, for a healthy body, you need a healthy lifestyle, and that involves healthy eating, regular exercise and plenty of rest. Athletes follow these rules to reach their peak performance, bodybuilders know that sleep is essential to building muscles and “cutting”. So, if your weight loss is becoming a challenge, and you do not know what to do next, sleep on it, and the problem may resolve itself overnight!
Sleep Research Shows to Sleep is Vital for Good Health
Sleep is not only good for your weight. Research carried out in the Duke-National University of Singapore Graduate Medical School has shown that sleep deprivation can cause short periods where brain function almost stops. A a study, imaging research was carried out on people who had been subjected to sleep deprivation.
People who are sleep-deprived experience periods of near-normal brain function, but these periods are interspersed with severe drops in attention, which has been compared to a moment of power failure in the brain.
The research, which was published in the Journal of Neuroscience, highlights the importance of preventing sleep deprivation for people that carry out critical tasks, such as operating machinery and night driving. The experiments used functional magnetic resonance imaging to measure brain blood flow in people who were either kept awake all night or allowed a good night’s sleep.
During imaging, researchers showed participants large letters made up of many smaller letters. Participants were then asked to identify either the large or small letters and to indicate their responses by pressing a button. Those participants with the fastest responses, both in sleep-deprived and well-rested conditions, showed similar patterns of brain activity.
However, those well-rested and sleep-deprived participants with the slowest responses – also known as attentional lapses – showed varying patterns of brain activity. During attentional lapses, researchers discovered diminished activity in the brain command centers in sleep-deprived compared to well-rested volunteers. This finding suggests that sleep deprivation reduces the brain’s ability to compensate for lost focus, something which is done automatically when alert.
Sleep-deprived people also showed reduced activity in brain regions involved in visual processing during attention lapses. Because the brain becomes less responsive to sensory stimuli during sleep, reduced activity in these regions indicates that during attention lapses, the sleep-deprived brain enters a sleep-like state.
It is not uncommon for sleep deprived people to “nod off” during work, and find it extremely difficult to stay awake and focused on a job. This research shows that this is because the brain is literally forcing a brief shut down in an attempt to get some much needed rest.
Sleep deprivation can be extremely dangerous, especially for people driving at night, or operating machinery or tools. A momentary lapse of concentration can be fatal. The only solution is to ensure that you get a the required sleep everyday.
Ideally eight hours per night, although sleep deprivation can be avoided with less sleep for some people, and the addition of 15 minute power naps during the day can be enough to prevent the brain shutting down on you.
Lack Of Sleep Can Cause CHD and Heart Attacks
Getting a good nights sleep can do more than just help you to lose weight, it will also help you to ward off heart disease. Researchers have found that there is a connection between lack of good quality sleep and heard disease. It seems that a lack of sleep can lead to an increase in blood pressure which is a trigger for heart disease. However, men seem to be unaffected by this. It is women who should ensure that they get enough sleep.
In the study it was found that women who consistently got less that 5 hours of sleep a night were twice as lifely to develop high blood pressure. High blood pressure (hypertension) is a serious risk factor for CHD (coronary heart disease). Heart disease is still one of the biggest killers, even after decades of advice on how to reduce risk.
Men Not Affected
Although in the study all groups had similar levels of smoking and drinking, the women who were deprived of sleep tended to have a poorer lifestyle and were more likely to be on medication, suggesting other factors at work.
The research mostly leads to the conclusion that you should ensure that you get at least 8 hours of sleep every night to limit the chances of developing high blood pressure and the associated risk of heart disease. It is also advisable to continue to reduce consumption of saturated fats and to also take regular exercise, as these both also reduce blood pressure and CHD risk.
So, in addition to eating healthily and exercising on a regular basis, getting a good nights sleep is also essential to long-term health and well-being.
Many people these days are working longer hours and after spending time with family, pursuing hobbies and sports, there is little time left in the day for a full 8 hours of sleep.
Chief researcher Francesco Cappuccio admits that at the moment the reason for the link is still not known and that more research is needed. However, there is a definite causal link. Combined with the studies that have shown that a lack of sleep can increase risk of calcification of the arteries and the studies which have shown that lack of sleep can lead to weight gain, there are many good reasons for ensuring that you sleep well at night.
However, a word of caution. Studies have also shown that people who get “too much” sleep each night are also at greater risk. Again, the reason for this is not clear, but it could be an indication of general poor health leading to increased fatigue.
1 in 3 People Do Not Sleep Enough
It is thought that around 1 in 3 people are not getting the recommended amount of sleep. This means that on average every other family is putting themselves at greater risk of a parent developing heart disease.
It is recommended that we sleep for 8 hours each night, and this should ideally be 8 hours of uninterrupted sleep. Sleep plays an important role in our health. It is a time for healing, repair, growth and recovery. Athletic and mental performance are both enhanced by adequate sleep and many professional athletes take an afternoon sleep to further increase recovery time.
However, there is also some debate over the 8 hours figure. Many people feel that 8 hours could be too much for some people, although not enough for others. The general advice these days is to aim for 7 to 9 hours of sleep each night but only sleep long enough for you to wake up feeling alert and full of energy.
- “Insufficient Sleep Undermines Dietary Efforts to Reduce Adiposity“. by Arlet V. Nedeltcheva, MD; Jennifer M. Kilkus, MS; Jacqueline Imperial, RN; Dale A. Schoeller, PhD; and Plamen D. Penev, MD, PhD. Annals of Internal Medicine October 5, 2010 vol. 153 no. 7 435-441
- “Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index“. Taheri S, Lin L, Austin D, Young T, Mignot E (Dec 2004). PLoS Med. 1 (3): e62.
- “Light at night increases body mass by shifting the time of food intake“. L. K. Fonken, J. L. Workman, J. C. Walton, Z. M. Weil, J. S. Morris, A. Haim, R. J. Nelson. Proceedings of the National Academy of Sciences, 2010; DOI
- “Sleep well and stay slim: dream or reality?” by Taheri S, Mignot E. Ann Intern Med. 2010 Oct 5;153(7):475-6. PubMed PMID: 20921547.
- “Sleep duration predicts cardiovascular outcomes: a systematic review and meta-analysis of prospective studies” by Francesco P. Cappuccio, Daniel Cooper, Lanfranco D’Elia, Pasquale Strazzullo and Michelle A. Miller. European Heart Journal (2011) doi: 10.1093/eurheartj/ehr007 First published online: February 7, 2011.
- “Association between Reduced Sleep and Weight Gain in Women” Sanjay R. Patel, Atul Malhotra, David P. White , Daniel J. Gottlieb and Frank B. Hu. American Journal of Epidemiology (15 November 2006) 164 (10): 947-954. doi: 10.1093/aje/kwj280
- “We are Chronically Sleep Deprived” by Michael H. Bonnet and Donna L. Arand. Published in Sleep. 18(10):908-911. 1995. Full paper available in pdf format.