Could sleep (well, the lack of it...) be sabotaging your weight loss? Recent studies in individuals with insufficient sleeping hours and/or circadian misalignment simultaneously present with changes in their metabolism and hormones that can hinder even the best weight loss plan.
So, how much can sleep have on your weight and overall health?
The lack of sleep and circadian misalignment* are associated with poor health outcomes which include an increased risk for weight gain and, ultimately, obesity. Studies reveal this risk to develop obesity can go as high as 38% (amongst other consequences such as diabetes, hypertension and cardiovascular disease).
Insufficient sleep is defined as sleeping less than 5-6h/day (sleep duration), however, rather than defining it as merely the number of hours, one must assess his/her levels of alertness, performance and health. Furthermore, sleep fragmentation (poor quality sleep) has to be taken into consideration when understanding what sufficient sleep implies.
*circadian misalignment includes irregular patterns of insufficient sleep-wakefulness and fasting-feeding cycles in relation to our "natural clock" and/or environment, or misaligned times between between central and peripheral rhythms.
The Sleep Cycle
Our sleep cycle can be divided in 4 stages being the third one the most regenerative (which usually begins in the 11 - 32min after we fall asleep). Worth noting our sleep cycle isn't uniform and we repeat this 4-stage cycle for several rounds where each cycle will differ in length.
In the third cycle (also called delta sleep or deep sleep), our body gets to restore bodily functions, recover, heal and promote growth. In a very summarised way, this stage impacts how our cells regenerate, immune system and overall health (including ageing processes).
Not less important, stage 4 (better known as REM sleep) is also very important for cognitive functions such as memory, consolidate and process new information (learning). It also impacts concentration and mood which can in turn highly impact our quality of Life.
How many hours should I sleep?
The UK guidelines for the required hours of sleep are between 7 to 9 hours (for adults) with the majority of sleep studies indicating 7 hours to be the very minimum we should be looking at.
With the increase demand and expectation from work, family, kids whilst not forgetting about yourself (would this mean a beauty ritual or a movie at the end of the day), it can be rather challenging to keep up with the sleep requirements.
Additional challenges that entered our lives without warning ranging from nearly constant use of screen-based technology as well as a ON button to reply and address emails, texts, calls or simply check social media "quickly" for a moment for pure enjoyment.
Altogether, our hormones will not be matching our "internal clock" timing when it comes to allow the body to relax and begin the first sleep cycle. So what are the real consequences besides the lack of energy, struggle to focus or the inconvenient waking up int he middle of the night?
The hormones affected by sleep (that we should really talk about)
Melatonin: hormone important for the sleep onset and circadian rhythm (read our 24-hour "internal clock") which is produced by our brain (in the pineal gland) in response to darkness. Therefore, the bright (blue) screen lights from screens or stimulating activities that may interfere with melatonin production may negatively impact the sleep on-set and reduce the sleeping hours that you will want to have!
Leptin: produced by fat cells, decreases appetite and can be found at lower levels during the day and higher at night on healthy individuals. In the presence of insufficient sleep, this hormone is decreased contributing to increased hunger levels. Together with Melatonin, both hormones can also impact thyroid metabolism and reproductive hormones which leaves more leads to the impact sleep can have at a much larger scale than we are currently aware of.
Ghrelin: produced in the stomach cells, ghrelin is a hormone that increases appetite. In healthy individuals with adequate sleep, this hormone increases between meals and decreases after meals. When looking at its levels in relation the the circadian rhythm, it increases across the biological day and decreases during the biological night. However, studies tell us that increased levels of ghrelin are not required to increase appetite (i.e. no significant changes for prolonged fasting periods or in hypocaloric diets) which is worth mentioning or it could mean an undesirable satiety when it comes to time-restricted eating or intermittent fasting.
When in the presence of insufficient sleep, this hormone is found to be increased (with implied increased hunger levels). Additionally, ghrelin seems to also impact sleep/wakefulness although this mechanism is yet to be fully understood.
Orexin: a neuropeptide hormone produce in the hypothalamus (also known as hypocretin) that regulates sleep/wakefulness, food intake, mood and metabolism. A decrease in orexin levels seem to be linked with an increased risk to develop obesity. In fact, a deficiency in orexin production is associated with metabolic changes, insulin resistance, metabolic syndrome and obesity likely to be explained by a decrease in energy expenditure.
Nutrition and sleep
Unhealthy diets
As a response to the ingestion of high fat, high sugar foods, our blood will present higher levels of glucose (sugar), insulin, leptin and other other hormones that induce sleep. Additionally, with an increase of body fat, the fat cells will produce more hormones (such as tumor necrosis factor-α TBF-α, interleukin-6 and leptin) that impair wakefulness.
Food choices: a healthy diet rich in foods that promote sleep (e.g. that help regulating melatonin) and non-stimulating of the nervous system, can be the key to a successful weight loss plan.
Chronotype:
Your natural circadian rhythm for sleeping and eating may highly impact the success of your food choices' timing and content. By understanding your type (morning, intermediate or evening), you can adjust to your "internal clock" needs and take full potential of your hormones. In particular for menopause as hormones natural move towards a new balance.
Time-restricted eating, intermittent fasting and shift workers:
What can present to be as a challenge for some (or by simply not being aware of its impact), eating during our biological night may disrupt our circadian rhythm and further aggravate overweight or promote weight gain (as hormones are not aligned with our food timing and/or content). Understanding which changes can be made and when will not only facilitate weight loss but also promote better sleep.
Is poor sleep stopping me from losing weight?
Insufficient sleep is associated with an increased risk to develop obesity in adults of up to 38% (especially in women). Moreover, sleeping one hour less (or lesser) than recommended 7 hours of sleep is linked to increased mortality, cardiovascular disease, diabetes and poor cognitive function.
How does it work? Hormones, metabolism and dysregulation of circadian rhythms!
- High body fat implies increased oxidative stress and insulin resistance that leads to a dysregulated metabolism;
- Poor food choices (likely linked to high-hunger profiles driven by unbalanced hunger hormones such as leptin and ghrelin, present when sleep is insufficient) that can contribute with and excess of up to 385kcal/day;
- Increased caloric intake (and lesser metabolic energetic needs) leading to a positive caloric balance (contributing to weight gain);
- Decreased synthesis of Growth Hormone (GH) with negative direct effects on the body fat (hinders use of fat as fuel via lipolysis - aka "fat burning" ) and muscle mass (less protein synthesis therefore les muscle growth).
- Potential increase in sedentary activities (e.g. screen time) contributing to decrease in energy expenditure, obesity and metabolic dysregulation.
- Prolonged circadian misalignment can result in weight gain (even if caloric intake and activity levels remains the same) as the "internal clock" is misaligned.
- Timing of food intake: later meals are linked to a low thermic effect of food (implying less energy expenditure) which often happens in sleep deprivation.
- Timing for exercise: morning exercise seems to be more favourable in weight loss and energy balance which can be compromised with insufficient sleep.
- "snowball effect": dysregulated hormones due to the presence of obesity (and likely unhealthy diet) will aggravate sleep deprivation which in turn will contribute to further aggravation of hormonal and metabolic imbalances.
Final thoughts & Advice
As further studies take place linking insufficient sleep with the risk and incidence of obesity, the current evidence corroborates the impact sleep deprivation has in our body which can sabotage a weight loss plan, whether this happens through consequent changes in our hunger levels (e.g. late and potential unhealthier meals) or via changes in our body hormones (such as melatonin and orexin as mentioned above).
Visit the Sleep Foundation website to find more about sleep and what you can start doing TODAY (and tonight!) to improve your sleep and your overall health.
To understand whether sleep is contributing to your weight gain and make the right changes to your health, contact me today to book a consultation or a discovery call.
For sources or further info on this content please email me at julietacoach@outlook.com
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