Scientists believe that getting enough sleep is a critical aspect of weight management; that is why recent recommendations mention adequate diet, exercise, water, and sleep. They found that sleep deprivation increases the levels of a hunger hormone and decreases the levels of a hormone that makes you feel full. This process may lead to overeating and weight gain. This would explain why new parents and night shift workers who are sleep deprived gain a great deal of weight.
A typical inaccurate understanding is that every person needs 8 hours of sleep per day. The truth is, the amount of sleep needed is different for every person and is individually and biologically determined. As a rule of thumb, 8 hours of sleep is suggested. Interestingly, sleep scientists tell us that we cannot ‘store up’ on our sleep by sleeping more on the weekend in preparation for the normal work week or vice versa. Another commonly held view is that the amount of sleep one requires decreases as one ages, but this is not generally the case.
Dr Eve Van Cauter, the director of the research laboratory on sleep, Chronobiology and Neuroendocrinology at the University Of Chicago School Of Medicine, extensively investigated the association between sleep deprivation and appetite stimulation. Her research revealed that sleep deprivation activates a small part of the hypothalamus, the region of the brain that is also involved in appetite regulation. She looked at two critical hormones in particular, both involved in regulating food intake: ghrelin and leptin.
Ghrelin is an appetite-stimulating hormone released generally by the stomach. When ghrelin levels are high, people feel hungry. In comparison, leptin, considered a satiety of fullness hormone, is released by the fat cells and signals the brain with regard to the current energy balance of the body. When leptin levels are high, a signal is sent to the brain that the body has enough food and the person feels full - while low levels of leptin indicate starvation and increase appetite. Van Cauter says: “One is the accelerator for eating (ghrelin) and the other the brake (leptin).”
Her research showed that the participants who slept for 4 hours a day had 18% lower leptin (brake) levels and 28% higher ghrelin (accelerator) levels. On top of this, the sleep-deprived participants who had the biggest hormonal changes said that they felt most hunger and craved carbohydrates-rich foods such as cake, candy, ice cream, and bread; whereas the participants who had the smallest hormonal changes reported being the least hungry.
Similar results were found by sleep scientists at the universities of Wisconsin and Stanford as well as at Columbia University. These studies tracked 1024 and 6115 people respectively.
What is interesting about these findings is that we used to think that sleep-deprived individuals used food to elevate themselves energetically from their state of tiredness; but the data now indicates that these individuals are indeed truly hungry due to a hormonal state.
With the understanding of the crucial link between lack of sleep and hunger, we can see how difficult it would be in a sleep-deprived state to adhere to one’s eating plan. Here are several strategies that you can use:
- Decrease the light level in your sleeping environment. Studies have shown that your brain can detect whether it’s day or night even if your eyes are closed.
- Classically condition your body to feel drowsy. Develop a bedtime routine 30 minutes before the time you would like to sleep. This routine should be calm and quiet so as to slow down your metabolic rate. Avoid stimulating activities such as using the computer, watching TV, playing video games, and doing office work or house work. However, reading should be fine. Try to ensure that the same 30 minute routine is the same each night so that this conditions your body to become drowsy.
- Ensure your sleeping position is comfortable and gives you enough support.
- You can listen to quiet, slow-paced music to facilitate sleep inducement.
- Do not use your bed for activities such as watching TV, doing your homework, or working on your laptop. It is important that both your body and your mind maintain an association between getting into bed and sleeping.
- Of course, avoid drinking beverages containing caffeine before bedtime (i.e.: coffee, tea, soft drinks, and energy drinks).
- Studies have shown that sleep inducement is increased when body temperature is lowered.
- Open a window or turn on a fan to cool down your bedroom.
- Try to avoid eating a large evening meal within 4 hours of bedtime. Large meals can cause discomfort and might interrupt sleep.