Weight Loss & Nutrition

Is Your Lack of Sleep Making You Fat?

By Danny Wallis Personal Trainer & Online Fitness Coach

February 16, 2015

Is your lack of sleep making you fat?  It’s an interesting question which most would scoff at and reply by saying “It’s too much laying about that makes us fat”.  In truth, the reality can be quite the opposite.

Balancing Your Health

It takes an equal balance of three components to lose body fat and feel the benefits of being fitter and healthier.  The first, of course, is exercise.  You cannot develop muscle and boost your aerobic and anaerobic fitness without the appropriate stimulus which exercise provides.

The second is nutrition.  No real surprise there.  We know food contributes towards about 70% of our results (or lack of results as the case may often be).  Food is fuel and getting it right contributes massively towards your overall training outcome.

However, what if you are training hard, eating what you feel is a nutritionally balanced diet and still not seeing the results you want?  The answer could be the third component to achieving your goals… Sleep!  More importantly, the right amount of good quality sleep (consistently).

Are You Working To Hard?

Let’s face it, life can be tough.  As an example – Work life; there is a good chance your 9am-5pm work day ends up being a minimum of 8am-6pm with emails and homework to address when you do eventually get home from your commute.  Oh, and lunch break? What lunch break?  Plus, if you add kids to the mix, forget it.  That’s a 24 hour job which never stops.  You are on call for life and a good nights rest becomes something you now fantasize about.

Habits & Routines

Human beings are designed to naturally feel tired at night when it gets dark.  We have a hormone which controls our sleep patterns that naturally spike when darkness sets in. However, this becomes a problem when we sit staring at a brightly lit box all night (insert TV, tablet, phone, laptop or gaming device into this space) because our bodies get confused and our sleep hormone production becomes affected. The bright light of the technology linked with the stimulus of what we are actually engaged with stimulates our brains and prevents us from wanting to sleep.

Linked with this night-time habit of staring at square things is the other habit we seemed to have adopted as a culture which is to eat late in the evening.  Restaurants open until midnight (some are 24 hour), eating after you get in late from work,  munchies at the cinema, or, most commonly, snacking in front of the TV are all things which become commonplace in most households.  This is no real surprise considering how busy our lives are and finding the time to eat during the day feels like an impossible task.

Eating Before Bed

Sleeping ManFeeding the body releases the energy from our food into our blood stream which then, in turn, gives our muscles fuel. The problem is eating before bed is a way of offering your body energy when we need it least.  This increase in blood sugar can interrupt or even halt your natural sleep patterns and is also a sure-fire way to pack on the pounds.

The mornings can be even more challenging.  The outcome of all this means we get to sleep too late and, when we do finally drop off, we don’t sleep well which means we then don’t want to get up.  We are designed to wake up naturally to the sun rising (after naturally going to sleep when the sun sets) but instead we have a little device next to our bed which screams at us way before we are actually ready to wake up and so the cycle repeats itself.

Daily Stress

Once we are at work we are faced with our usual stressful routines.  Deadlines, office politics, budget constraints, challenging work based problems, etc…  It’s a stressful time.  The other problem in addition to this is we are now tired, possibly feeling run down and that means we need a pick-me-up.

We are much more likely to eat too much when we are tired. Your blood sugar levels will be unusually low as your body hasn’t recovered and rested properly from the night before and, therefore, our subconscious knows sleep at work isn’t possible. Instead, it tells us to source energy from elsewhere… and it wants energy fast!  Enter the chocolate bar, large coffees, snacks, sweets, etc… Comfort eating on all the wrong things.


As a result of eating nutritionally poor/sugar rich food, your blood sugar levels will be affected.  This sugar absorbs into your blood stream quickly and provides a huge hit of energy… Much more than you can use all at once.  The body has a unique way of ‘banking’ the calories consumed as a means of storing it for later.  If we lived in the wild, this is a fantastic survival mechanism.  However, in everyday life ‘banking’ excess calories simply means getting fatter.

We have to consider what happens to our body as an outcome of a lack of quality sleep. Sleep is when we repair and grow.  This is essential if you are training because all a ‘workout session’ essentially does is break you down. It’s actually sleep and nutrition which build you back up again making you leaner, fitter and stronger.

Recovery From Training

A lack of appropriate rest means the repairing process becomes hindered.  Your muscles will become stiff and sore, your immune system starts to suffer making you more susceptible to illness and your energy is, of course, at rock bottom. This means your mood changes along with your mindset.  Where before you were energised, focused on eating healthily and pushing your body hard in the gym five days a week, now all you want to do is eat stodgy comfort food and curl up under your duvet. No surprise when your once ‘toned body’ is now looking like a much saggier version of its former self.

Your body changes hormonally when you are sleep deprived as well. Cortisol is a hormone which spikes in the body when exposed to high amounts of stress, especially physical stress.  High levels of Cortisol is not our friend – It is a hormone which can create a catabolic effect on the body.  So, as a means of repairing your immune system and tissues, in the absence of sleep, your body can start to break itself down – Your own proteins (to be specific) order to facilitate this.

Protein in your body is found in your muscle, skin and organs… Basically, all the really important bits.  As a side effect of your body consuming itself to keep you functional, your body will revert back to ‘banking’ dietary calories in order to keep you alive and as well as possible.  This means your healthy food and gym habits (designed to burn fat and build muscle) are flipped on their head by the Cortisol hormone which turns your body into a fat storing, muscle burning machine. Not good.

The Remedy

All of this can be remedied with new habits.  Ensure you have an appropriate bedtime which will offer you a minimum of seven hours sleep a night and stick to it.  If you work at/from home, make sure you have a cut off time for work in the evenings.  Manage your time better during the day with food so you don’t need to eat so much late at night.  Oh, and stay away from your ‘square things’ to late into the evening to allow time for your brain to wind down and relax.

A good nights sleep is like a wonder drug.  You wake feeling fresh, fit, energised and ready to take in the world.

I wonder… When was the last time you felt like that?…

About the author

Danny Wallis is a Personal Trainer, Sports Therapist, NLP Life Coach and Nutrition Advisor, with over 20 years experience in helping people achieve their goals.

Danny Wallis

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  1. Hi Danny, I have been exercising with BGE for some time – usually joining Paul on a Monday – great class. Finally got round to looking at your blog thanks to a nudge from the BGE newsletter! Great blog – really good, clear, well written articles which I found both helpful and interesting, all very motivating! Thanks Marianne

    1. Hi Marianne,

      Thank you so much for the lovely feedback, I really appreciate you spending the time to visit my blog and to take the time to comment. I am so pleased that you like it and that it’s able to help you. Please feel free to subscribe if you would like my future posts emailed to you directly. D

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