One of the most surprising results from sleep deprivation is the fact that it can lead to weight gain. There is a clear link between sleep and the peptides that regulate our appetite. Ghrelin stimulates hunger, whilst leptin suppresses it and shortened sleep time has been proven to be linked to decreases in leptin and increases in ghrelin.
What does this mean in plain English? If we feel sleepy in the day, most of us are guilty of reaching for the quick fix of coffee and something sweet and sugary to boost our energy levels. Comfort food is the go-to for many people if they’re feeling low in energy. In addition, many people find they don’t have time to cook in today’s hectic world and so resort to takeaways – high in calories and fat.
The immediate results from eating these kinds of food is that we can starve off sleepiness for a short while. But if you aren’t getting enough sleep overall, your body will begin to suffer. Author of Beauty Sleep (Beauty Sleep: Look Younger, Lose Weight, and Feel Great Through Better Sleep ), Michael Breus PhD explains that, “It’s not so much that if you sleep, you will lose weight, but if you are sleep deprived, meaning that you are not getting enough minutes of sleep or good quality sleep, your metabolism will not function properly.” Sleep deprivation can fool your body into thinking it’s in danger, slowing your metabolism in an effort to maintain its resources.
In a study carried out by the Kaiser Permanente Centre for Health Research (based in Portland, US), research found that people who had less than six hours sleep (or, somewhat surprisingly more than eight hours) per day were less likely to achieve weight loss than those who had between six and eight. High stress levels were also found to affect weight loss and, when combined with poor sleep, subjects were about half as likely to successfully loose weight.
In addition to the links found between sleep and the peptides mentioned above a lack of sleep also boosts your level of the stress hormone cortisol. And this also increases your appetite. The body’s reaction to stress is to try and produce serotonin to calm you down and the easiest way to do this is to eat high-fat, high-carb foods that produce a neurochemical reaction. But, because you’re tired, your body’s ability to process sweet food is hindered. Essentially the mitochondria in your cells that digest start to shut down, leaving sugar in your blood and high blood sugar. A study in the Annals of Internal Medicine suggests that a lack of sleep can make fat cells up to 30% less able to deal with insulin.
It’s pretty clear to see that sleep is one of the most important factors in maintaining a healthy weight, preventing weight gain and even aiding weight loss. If you’d like to read more on the subject, these books are a good starting point:
The Sleep Diet (ebook)