There are multiple studies and experiments that demonstrate the impact of lack of sleep on our waist line. Despite this, too few of us are getting enough. Today I explain why lack of sleep can hinder your weight loss and suggest some tips for how you can get regular restful sleep if that is something that you struggle with.
70 years ago, more than 80% of the American population got seven or more hours sleep a night, now it is less than 60%. Scientists from Oxford university claim that we are sleeping on average one or two hours less a night than we were 70 years ago. And a study of US adults found that 30% are sleeping less than six hours a night.
Lack of sleep contributes to a wide range of health issues including depression and anxiety, obesity, type II diabetes Alzheimer’s.
If you want to lose weight, making sure you get at least seven hours quality sleep each night. Multiple studies have found dramatic increases in incidences of obesity in people who get too little sleep or poor-quality sleep.
A major observational review found that short sleep duration, less than seven hours per night, increased the likelihood of obesity by 89% in children and 55% in adults. Another experimental study, where adults were allowed just five hours of sleep per night for five nights, found that they gained an average of 1.8 pounds over the short course of the study.
Many studies have found that people who are sleep-deprived have an increased appetite. It’s thought that this is likely caused by changes that sleep deprivation creates in relation to two important hunger hormones, ghrelin and leptin.
Ghrelin is a hormone released in the stomach that signals hunger in the brain. Levels are high before you eat, which is when the stomach is empty, and low after you eat. Leptin is a hormone released from fat cells. It suppresses hunger and signals fullness in the brain. When you have inadequate sleep, the body makes more ghrelin and less leptin, leaving you hungry and increasing your appetite.
A study of over 1,000 people found that those who slept for short durations had 14.9% higher ghrelin levels and 15.5% lower leptin levels than those who got adequate sleep.
In addition, the hormone cortisol is higher when you do not get adequate sleep. Cortisol is a stress hormone that is also linked to an increase in appetite.
Lack of sleep alters the way your brain works. This may make it harder to make healthy choices and resist tempting, high dopamine producing, foods. Sleep deprivation will reduce activity in the pre frontal cortex, the thinking part of your brain, and increases activity in your primitive brain, or toddler brain as I like to call it. This primitive brain is more likely to be stimulated by food when you are sleep deprived.
This could be why you are more likely to seek snacks and comfort food after a bad night’s sleep. It’s not your fault you have less self-control, it’s because your brain is working differently.
A study observed the effects of sleep deprivation on food intake. When participants were only allowed four hours of sleep, their calorie intake increased by 22% (559 calories), and their fat intake almost doubled, compared to when they were allowed eight hours of sleep.
This increase in calories may be due to increased appetite and poor food choices, as mentioned above. However, it may also simply be from an increase in the time spent awake and available to eat. This is especially true when the time awake is spent being inactive, like watching television.
Insulin resistance is a precursor for both type 2 diabetes and weight gain. Insulin is a hormone that moves sugar from the bloodstream into your body’s cells to be used as energy. When cells become insulin resistant, more sugar remains in the bloodstream and the body produces more insulin to compensate. The excess insulin makes you hungrier and tells the body to store more calories as fat.
In another sleep study, men who had four hours of sleep for six nights found their bodies’ ability to lower blood sugar levels decreased by 40%.
To summarise, poor sleep and too little sleep dramatically alters the way the body responds to food. Not enough quality sleep leads to increased appetite, a desire to eat more often and larger portion sizes, and a desire to reach for high dopamine comfort foods.
To make matters worse, it can become a vicious cycle. The less you sleep, the more weight you gain, and the more weight you gain, the harder it is to sleep.
Ten tips to help you ensure you get enough good quality sleep
If you would like to talk through how sleep is impacting your ability to lose weight book a weight loss consultation phone call today.