It is not yet widely known that there is an important relationship between weight and sleep. When you are trying to lose weight, getting insufficient sleep can make the task much harder. A helpful book by Dr Michael Breus, “The Sleep Doctor’s Diet Plan” underlines the importance of good sleep in being able to lose weight.
People who sleep less have a slower metabolic rate
Sleep deprivation leads to a number of changes. Changes in glucose metabolism mean that the food you eat isn’t burned as efficiently and instead is stored as fat. During sleep the brain secretes a large amount of growth hormone, which is involved in the breakdown of fat for energy. When you have insufficient deep sleep there is less growth hormone available to break down fat. It is also of note that in a study quoted by Dr Breus, when dieters got adequate sleep the weight they lost was fat. When they slept less (5.5 hours) they lost mean body mass.
Poor sleep increases appetite
Lack of sleep leads to a lowering of the level of the neurotransmitter serotonin and the body’s response is to eat serotonin-increasing foods (those which are high in carbohydrates). It seems that when sleep deprived, the brain craves glucose (its main source of energy) and the appetite for carbohydrates becomes particularly strong.
Poor sleep also alters the level of key hormones involved in regulating hunger and fullness. Sleeping less than 6.5 hours a night causes leptin (the hormone that registers fullness) to reduce and ghrelin (the hormone that registers hunger) to increase during the day, so you are likely to feel more hungry and be less able to notice fullness when you have had insufficient sleep.
Michael Breus quotes a study in which people were allowed to sleep 5.5 hours one night and 8.5 on another and their consumption of free snacks was measured the following day. They ate an average of 220 calories more when they had less sleep the night before.
Poor sleep depletes willpower
Baumeister and Tierney’s book “Willpower” describes the importance of sleep in replenishing willpower each day. Insufficient sleep compromises the amount of willpower we have.
What can you do to do to improve sleep to aid weight loss?
Professor Colin Espie is an expert on sleep and insomnia. His book, “Overcoming Insomnia” and his online course at www.sleepio.com both provide useful information on improving sleep.
Going to bed very late not only reduces the amount of sleep you are likely to get but also gives you more time to get hungry again and eat. The longer you’re up at night the more likely you are to snack. If you are eating late into the evening, you may find it helps to shut the kitchen door and move into your bedroom and establish late night habits which are away from food. Taking a hot drink with you may help the process of stopping late evening eating.
Your evening wind-down period is important in getting your body ready for sleep. A regular routine in which you go through the same series of actions each night in the hour before going to bed can help improve your sleep. This should include slowing down then stopping any work or other activities and switching to a relaxing activity before doing the immediate pre-bed activities of brushing teeth, putting pyjamas on, setting your alarm clock and so on.
If you tend to use screens in the evening, the blue light exposure from TVs, laptops and other devices in evening can delay the release of melatonin, making it difficult to fall asleep. Downloading the free programme f.lux from www.stereopsis.com onto your device filters out some of the blue light (ie the wavelengths that cause the problem) in the evening. The programme is timed to coincide with your local time zone. The link is https://justgetflux.com/.
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