by Fiona Wing
A recent study* conducted over a 15 day period showed that people who got 4 hours of sleep or less for as little as 5 nights in a row gained on average 820gm. Furthermore, when those folks transitioned from poor sleep to adequate sleep, they lost up to 0.5kg during the study.
The balance between energy renewal through both adequate sleep and food intake, and energy expenditure during the day is very find and extremely important for maintaining a metabolic homeostasis.
When the scales are even, your metabolism runs smoothly and your appetite and weight is managed easily. When the balance is tipped, metabolic disruption ensues and recent research has identified some interesting links between a lack of adequate sleep and weight gain.
According to the Woolcock Institute of Medical Research, sleeplessness effects up to 34% of Australians at some point of their lives, while around 10% of us experience sever insomnia on an ongoing basis.
Sleep gives you the opportunity to recharge your batteries and get ready for the day ahead. Sleep is also the time when your body grows and repairs damaged tissues, creates hormones, clears wastes and metabolic toxins, creates new brain pathways (influencing memory and cognitive function), and fights bugs and infections
Inadequate amounts of sleep causes a need to burn more energy throughout the day in order to “keep going through tiredness” or sustain prolonged wake time. A recent study has found that insufficient sleep therefore cues the production
of hormones that increase appetite so that you can gain those extra calories needed for energy from food. In the overall scheme of metabolism in the body, this seems to make sense. However, it has been found that lack of sleep can cause disruptions in both the production and function of a number of hormones and neurotransmitters that have a bearing on energy expenditure and conservation, and this can lead to the intake of calories over and above what is required to get you through the day on limited sleep. Interestingly, these hormones and neurotransmitters not only have roles in the maintenance and regulation of appetite, but also on food choice.
Hunger Hormones and Sleep
Ghrelin is a hormone that is increased when adequate sleep is not achieved, and its function is to stimulate the appetite, to provide extra energy for tired cells.
Leptin is a hormone that controls your appetite. It signals to your brain that you are full and have had enough food to meet energy demand. Leptin production is decreased when you don’t get enough sleep.
Peptide YY is a hormones that is produced in the small intestine in response to a meal. It stifles appetite and creates a sense of fullness during and after a meal. Lack of sleep causes a decrease in Peptide YY production.
Insulin sensitivity also drops when you don’t get enough sleep. This causes carbohydrate cravings and blood sugar imbalance. Interestingly, research has found that diets that are high in carbohydrates tend to decrease the production and release of Peptide YY, and diets that are higher in protein will increase its production and release. Sleeplessness is therefore likely to lead to a cycle of high carb intake, poor Peptide YY production, and increased hunger.
Cortisol is a hormone that is linked with the stress response. Too little sleep increases cortisol production from the adrenal glands (like caffeine shots) to try to provide more energy for the day ahead. Cortisol signals your body to conserve energy (ie. hold on to weight). So the overall picture is that not getting enough sleep increases your appetite and decreases your sensation of fullness, leading to overeating both at meal times and snacking throughout the day and into the night thus possibly leading to weight gain. It leads you to crave high energy food sources such as high carbohydrate and fatty foods and decreases your ability to say “no” when a snack is on offer, again potentially leading to weight gain. Sleep deprivation also makes your body think that it is constantly under stress and prolongs cortisol production leading to energy conservation and thus weight gain.
So, how much sleep in enough? Most of the research suggests that 7-9 hours each night is optimal; however, this can vary from person to person. As long as you are waking feeling refreshed and ready to tackle the day, you should be getting enough sleep. If you find it difficult to respond to your alarm, have to hit snooze button a few times and find yourself fatigued and tired throughout the day, changes are you are not getting enough sleep. If you are having trouble sleeping at night , a good sleep hygiene routine is a must.
Your routine might include:
Moderate exercise late in the afternoon or early evening – which will have your temperature decreasing by bedtime – one of the triggers for sleep;
A nice warm bath using some chamomile, lavender or lemon balm oil and magnesium salts for relaxation;
Dimming the lights around the home as the sun goes down which helps stimulate Melatonin production;
Turning off “screens” at least one hour before bedtime
Swapping screen for a book;
Including protein (especially spinach, eggs, poultry and cheese) with your dinner to help with the production of neurotransmitters that assist with sleep such as serotonin;
Quiet meditation and breathing exercises.
Making time for a good night’s sleep is just as important for weight loss as planning a healthy diet and exercise routine. By balancing energy expenditure with energy renewal, metabolism is able to occur optimally and your weight can be managed quite easily – even with your eyes closed.
*Markwald, R. R. et. al. “Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain” Proceedings of the National Academy of Sciences USE 2013; 110(14):5695-5700
More from the Caruso’s Blog: