Sleep (part 2): Stress, Weight loss and Improving Sleep Hygiene

By: Dan Carpenter

Approximately 9 Minutes Reading Time


Brief Article Overview


  • Chronic sleep deprivation (<6hours sleep a night, most nights) is highly prevalent in today’s society.
  • Obesity, metabolic syndrome and elevated stress levels are not only strongly associated with chronic sleep deprivation, but interact with each other, forming multiple positive feed back loops.
  • These feedback loops have been shown to contribute to all cause mortality.
  • Improve your sleep by;
  1. Keep regular: Try to keep a consistent 8hour “window of opportunity” to sleep at regular times.
  2. Take time to unwind: 30-60min before bed, switch off mentally stimulating devices and (phones, TVs, laptops etc) and adopt a routine helps you unwind e.g: taking a bath, listening to calming music, meditation or reading.
  3. Improve your sleeping environment: Keep your bedroom clean, tidy, cool and dark.
  4. Avoid Sleep Disrupters: stop drinking caffeinated beverages less than 6 hours before bed and reduce alcohol intake.


Optimum vs Minimum


In our previous article we identified that a large percentage of the general population are regularly getting less than 6 hours of sleep a night. In terms of sleep length, there is a difference between optimum and minimum. The current research is pretty clear….6 hours of actual sleep (not just time in bed) a night is the minimum dosage, before health and wellbeing starts to decline. I think we can all agree that’s a realistic goal. 


The classic “8 hours a night”, is the optimum, which has been derived from systematic reviews investigating correlations between sleep, health and mortality (10). This is the recommended sleep length for optimal physical and cognitive function. But for the sake of this article we can confidently agree that consistently getting less than 6 hours of sleep, most nights, can be classed as “chronic sleep deprivation”. 


Don’t get us wrong, we understand that life is to be lived. You other prioritise in life social, family and work. The occasional bad night’s sleep will not likely have significant long-term detrimental effects on your wellbeing (unless you’re driving a car or operating heavy machinery!), but chronic sleep deprivation can be corrosive to your health. 


Sleep and Stress


The Autonomic Nervous System (ANS) stems from the brain, down your spinal column and branches out to innovate and intertwine all of your bodily systems and functions. It acts in response to it’s internal and external environment, in order to meet any required demands. The ANS is split into two distinct pathways;


  1. Parasympathetic: dominant when the body is perceived as safe and relaxed, priming the body for recovery and restoration.
  2. Sympathetic: dominant when the body is perceived to be under threat and/or stimulated, to prime the body for action. 
Sympathetic and Parasympathetic Neural Pathways

These pathways are always working in tandem, but each one will “dominate” depending on how the brain perceives its environment and what the body is physically doing. Most of your waking hours are spent in a sympathetic dominant state. Sleep is the only truly parasympathetic dominant activity we regularly perform. Balance between these pathways is crucial for optimal health and wellbeing.


When you get insufficient sleep, your body will respond as if it were in a threatening environment. This is known as a sympatho-adrenal response, defined by a multitude of physiological responses, all initiated by the release of stress hormones from the Hypothalamus Pituitary Axis (HPA), which increases alertness and primes the body for action. These processes are vital in temporary bouts, but can be toxic to your health if left in a chronic state. 


The Stress Hormones of note are Adrenaline (Epinephrine) and Cortisol. Adrenaline increases heart rate, elevates blood pressure, expands lung capacity, and sends blood to muscles, whilst Cortisol shuttles sugar (glucose) into the bloodstream and suppresses digestive, immune, reproductive and growth processes. 


Remember these hormones, don’t cause stress, they occur in response to stress, which initiates a cascade of physiological processes. 


Naturally, these hormone levels drop after the perceived threat has passed. When sleep deprivation is chronic, this sympathetic tone remains elevated which, in turn, can lead to further sleep deprivation. Unfortunately, it’s quite easy to fall into a perpetual sleep deprivation – high stress positive feedback loop, which can spiral out of control and may contribute to a plethora of health issues including obesity and metabolic syndrome. 

Stress and sleep deprivation positive feedback loop
Sleep and Weight Gain


Sleep deprivation has been consistently and repeatedly linked with weight gain (1), obesity (2,3) and adverse metabolic responses (4). The consistency of this phenomena has led to a myriad of proposed mechanisms.


One popular mechanism is that sleep causes levels of one hormone (Leptin) to rise and another (Ghrelin) to fall (5). Leptin suppresses appetite and Ghrelin stimulates appetite, so you don’t feel hungry when you sleep. Chronic sleep deprivation disrupts this cycle, causing average Leptin levels to fall and Ghrelin levels to rise, signalling a state of famine (no matter how well nourished you may be). This could, in part, explain the reason people who are sleep deprived experience higher rates of cravings, snacking, number of meals eaten per day and preference for energy rich foods. (6). 


Interestingly, eating in the absence of hunger also increases when sleep is restricted. New neuroimaging (fMRI) experiments have provided evidence that insufficient sleep increases the brain’s pleasure response to food (known as a hedonic response) especially when said food is hyper-palatable, high in sugar and fat (7,8). 


Decision making is also negatively affected by sleep deprivation. Another fMRI study highlighted that short sleep alters functional connections between the prefrontal cortex and the brain’s reward- and emotion-processing centers, impairing so-called “executive functions” (9). As a result, we become hypersensitive to rewarding stimuli, our emotional responses are heightened, and we start acting “irrationally”, all of which can contribute to increased caloric intake.


Other simple and fairly obvious mechanisms include the link between fatigue and reduced energy expenditure, as well as more time awake meaning more opportunity to eat! 

Sleep deprivation and weight gain
Strategies For a Better Night’s Sleep



1. Keep a Regular Sleeping Pattern


We should aim to go to bed and wake up at the same time each day. People generally have a hard time adjusting to changes in sleep patterns. Unfortunately sleeping late on weekends doesn’t make up for poor sleep during the week. 




  • Because of our family / work commitments, our wake up time’s are usually routine. Use this regularity to reverse engineer your bedtime and stick to it.
  • Give yourself a 30min time window to unwind, 15mins to fall asleep, an 8 hour opportunity to sleep and 15min to gradually wake up. For example: 
Sleep time planner


2. Set Aside Time to Unwind


This doesn’t mean sitting on the sofa binge watching Netflix! This means entering a state which primes your mind and body for sleep. Set an alarm at least 30mins before you want to go to bed and establish a pre-bed routine.


The strategy: 


  • Turn off the TV.
  • Get away from your phone and laptop (this is a notoriously difficult one). 
  • Turn the lights down. 
  • Do something relaxing such as: breathing, stretching, foam rolling, having a bath, meditating, reading a book, etc.



3. Improve your Sleep Environment


The environment in which you sleep can have a profound effect on your ability to nod off. Here are some simple rules to follow to improve the odds of a good night’s sleep:


The Strategy:


  • Keep your bedroom clean and tidy – messiness often reflects in your thoughts, there’s nothing better to sleep in than clean fresh sheets and a tidy room…am I right?! 
  • The darker the better – light is a stimulant, which your body is very sensitive to, even if your eyes are shut. Invest in thick blinds, keep the LED electronic devices to a minimum or use an eye mask.
  • Keep it cool – A gradual temperature drop is another cue your body uses to initiate it’s sleep mechanisms. Set your thermostat to a cool, but comfortable 15-20ºC (60-67ºF) about an hour before bedtime. You can schedule this on modern thermostats nowadays. 



4. Adopt a Caffeine Curfew


Now, in an ideal scenario, we wouldn’t need the aid of stimulants to feel awake, but a coffee in the morning and/or before a workout isn’t the end of the world!

It’s important to note, however, that caffeine has a half life of 5-6 hours (this does vary between individuals). Nonetheless, this can mean that the caffeine from your after-dinner coffee/tea/caffeinated soda at 8pm will still be having a significant stimulatory effect until at least 2am! 


The Strategy: 


  • This one’s simple, don’t consume caffeinated beverages beyond 4pm. 
  • Replace with de-caffeinated alternatives if necessary. 



5. Skip the Night Cap 


Alcohol can have a detrimental effect on sleep quantity and quality. After a few glasses, or pints, or bottles(!) you may find that you can fall asleep fairly quickly, but experience multiple “mini-awakenings” during the night. This can be the reason you feel so tired and lethargic the next day, a big contributor to that dreaded hangover (enter the “never again” monologue). 


According to the National Sleep Foundation, alcohol reduces the quality and quantity of your sleep in the following ways:


  1. It activates different sleep rhythms simultaneously, which battle against each other, causing multiple disturbances. 
  2. It blocks REM sleep.
  3. It’s a diuretic, which means multiple trips to the bathroom! 


The idea of the night cap is therefore paradoxical, and according to sleep expert Matthew Walker:


“Alcohol sedates you out of wakefulness, but it does not induce natural sleep” 


The strategy: 


  • Don’t use alcohol to unwind at the end of the day.
  • Replace this strategy with an unwind tool previously mentioned. 




We hope our sleep articles (part 1 and 2), have highlighted the importance of getting good quality, regular sleep of sufficient quantity. The intent of these articles was not to simply tell you to get more sleep, but to investigate the reasons why sleep is important, the causal mechanisms between sleep and some select health outcomes, and then to suggest actionable steps towards improving your sleep hygiene. 


These suggestions are a good start, but remember that it’s ultimately up to you when it comes to taking your health into your own hands! Sleep is non-negotiable, so why not experiment with your pre-bed routine and find what works for you! 




Food for thought? If this has encouraged you to think about your health, fitness & wellbeing, why not click this link and fill out our enquiry form. We’d love to see how we can help you on your journey.


Disclosure: This article is not to be used as medical advice. If you are currently experiencing physical or mental health issues, please seek professional advice from a fully qualified Nutritionist, GP or Physiotherapist. 





  1. Short Sleep Duration and Weight Gain: A Systematic Review. (2008) Patel, S. and Hu, F. 
  2. Meta-Analysis of Short Sleep Duration and Obesity in Children and Adults(2008) Cappuccio, F., Taggart, F., Kandala, N., Currie, A., Peile, E., Stranges, S. and Miller, M.
  3. The link between short sleep duration and obesity: we should recommend more sleep to prevent obesity. (2006) Taheri, S.
  4. Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index. (2004) Taheri, S., Lin, L., Austin, D., Young, T. and Mignot, E. 
  5. A single night of sleep deprivation increases ghrelin levels and feelings of hunger in normal-weight healthy men. (2004) SCHMID, S., HALLSCHMID, M., JAUCH-CHARA, K., BORN, J. and SCHULTES, B. 
  6. Eating patterns and nutritional characteristics associated with sleep duration. (2011). Kim, S., DeRoo, L. and Sandler, D. 
  7. Acute Sleep Deprivation Enhances the Brain’s Response to Hedonic Food Stimuli: An fMRI Study. (2012) Benedict, C., Brooks, S., O’Daly, O., Almèn, M., Morell, A., Åberg, K., Gingnell, M., Schultes, B., Hallschmid, M., Broman, J., Larsson, E. and Schiöth, H. 
  8. Sleep Deprivation Selectively Upregulates an Amygdala–Hypothalamic Circuit Involved in Food Reward. (2019) Rihm, J., Menz, M., Schultz, H., Bruder, L., Schilbach, L., Schmid, S. and Peters, J. 
  9. Sleep deprivation: Impact on cognitive performance. (2007) Paula Alhola, P.
  10. Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies. (2010)Cappuccio, F., D’Elia, L., Strazzullo, P. and Miller, M.