Sleep Part 2/3: Bad sleep, disease & how to avoid them

Sleep two

Here’s part two … er … you still with me?

Yesterday in part one we introduced sleep, what it is, the context and the ways in which altered sleep quality can alter health, but just how does sleep actually affect your health, body composition and performance, and what can you do to improve it?

As far as improving sleep goes, well, as you may have already guessed there’s a few different options to try and how effective of each one will be for you depends upon the individual.

Similarly poor sleep quality or duration affects us all but the effect is slightly different from person to person. Regardless, they’re all factors that make it harder for you to keep the weight off and your body and brain happy and healthy though. Let’s break down what what they are.

How sleep alters health and function

Sleep, health and death

We know from a lot of big studies that there’s a sweet spot with sleep, studies that look at all-cause mortality, in other words death from any cause, identify a pattern 8 hours sleep tends to be the best for you, for the general population in the UK, or the other side of the world, it doesn’t matter. Sleeping longer is not good nor is sleeping shorter either.

Sleep and appetite

The regulation of appetite, what you want to eat and how much you eat we’ve discussed a in a little detail already (see The DODO Diet page XXX) already. The research is pretty clear that there’s a connection with food intake and sleep quality or duration.

People who don’t sleep much will tend to be fatter and also have increased energy intakes, the affect is even seen children who report better diets when sleep duration is increased. The point is that though this info is interesting is the sleep the cause or just correlation? It’s hard to be sure and we do know that general eating behaviours have a lot to do with it but research shows that satisfaction from a meal is lower in sort duration sleepers, but what is clear is that short duration sleep is connected with insulin and leptin and ghrelin, altering the functioning of the mechanism that balances your energy intake.

Sleep and sugar metabolism

This connection between overly short (and long) problems with blood sugar regulation and insulin metabolism seems pretty clear cut. In fact researchers and clinicians agree that in cases where sugar/insulin metabolism is out of whack looking for possible causes should also include looking at sleep quality, in fact the research shows that in people with sleep problems causes by their weight you can actually improve glucose metabolism by improving their sleep

Sleep and fat metabolism

The research is mixed when it comes to whether or not poor sleep cuts your total energy expenditure over the day. If I had to take a guess I would say it would not, however the balance of what you burn carbs vs fats is altered, with your body switching over to burning more sugars, this, allied with the poorer diet and control of appetite could mean big problems in the long run.

Sleep and the immune system and cancer

We know from the research that shift workers seem to have higher rates or certain diseases like cardiovascular disease, inflammatory conditions and so on, the mechanism appears to revolve heavily around melatonin. The production of this hormone in the evenings is inhibited by exposure to light and this has big consequences for the immune system and is involved in the development of cancer.

Sleep and mental health

Sleep deprivation effects mood, memory and other cognitive functions, both in adults and children, we know of course that as we age we tend to sleep less and though once thought ‘natural’ we now know that these reductions in sleep duration are connected with the development of depression. So it seems no matter your age sleep is important for the health of your brain and your body.


Sleep duration and quality – the factors that control this

Everyone knows periods where because of family life, work, or social schedule we’ve got by on a lot less than we would like to. Here we generally think in terms of a sleep debt that, hopefully – we can make back up by sleeping longer for a few days. Your sleep duration and quality is controlled largely by the following

  • Your genes

Your particular genotype, there exists a few different alleles for genes associated with sleep duration.

  • Your Health

Being overweight or having prostate problems for example, these can both fragment sleep.

  • The environmental #1: Chemical

The food you eat, the drinks you consume and the drugs supplements you take

  • The environmental #2: Physical

        The noise, the light, the temperature and so on

  • Behavioural

        The worries, the habits and other elements of your life

Dwelling on these factors for a minute is be worthwhile if you have sleep problems because these factors inform how you might go about identifying the potential causes

 But …how much should you sleep

OK so some may, genetically, be pre disposed to ‘needing’ less sleep but the research is painting an ever clearer picture, if you want the best health then 7-8 hours a night is the duration to aim for. In practice aiming for more about 8.5 hours is probably smart as life gest in the way


How to improve your sleep

sleep three

Sleep Hacks

So how do you improve yours easily and quickly? There’s been a rash of sleep related sleep blogs recently, I prefer to look at things in terms of action and habits in the timeline running up to be and after and then also the environment. Enter the idea of lifestyle ‘hacks’.

This is simply a term for sexing up what are quite often very sensible, effective but mundane changes to your environment or habits.

These hacks fall into three areas,

  1. What you do in the hours before you go to bed
  2. Setting the environment – both the one you’re in before be and the sleeping environment
  3. What happens after you go to bed.

There’s some overlap and some general themes. Also it’s not rocket science but things don’t have to be flashy to work.


Before bed

5-7 hours before:

Cease caffeine intake.

This includes coffee, tea, energy drinks and many fizzy drinks. Caffeine has a half life of about 5-6 hours so depending on how sensitive you are you may want to stop earlier. If using a caffeine boost before an evening training session play around with the dose.

3-4 hours before:

Avoid very spicy foods.

These stimulate the sympathetic nervous system – the fight and flight response –  so will raise heart rate and body temperature and delay sleep onset

Write a ‘to-do’ list.

Get everything you need to do down a piece of paper, important or not. You can sort out priorities tomorrow morning, but for now rest safe in the knowledge that you don’t have to remember a thing. Do it three or more hours before bed because you’ll often find that one thought leads to another and some more tasks will occur to you in the next couple of ours.

1-2 hours before:

Unless otherwise needed, such as hot weather or a late gym (or pub!) session, reduce water intake. This will help you avoid having to wake up to go to the toilet.

1 Hour before:

Signal to your body it is bedtime

- Reduce the temperature in the house, open the windows or adjust the heating.
- Dim the lights a little, and
- Stop using anything with a screen like TV’s, computers and smartphones. This is incredibly important as all this helps to trigger melatonin release, which is the hormone that drives sleep.


Light Melatonin, your sanity and your love handles

Light is a potent signal to the body, it helps regulate your sleep/wake cycle and directly influences ancient time keeping apparatus in the brain that controls the ‘circadian rhythm’ the daily cycling of hormones, different types of brain activity, even things like when you go to the toilet.

The environment’s impacts on your health and there’s nothing different about sleep. It turns out that we’re designed and calibrated to go to sleep when it gets dark (and cooler)

Melatonin, the sleep hormone is produced when light levels drop towards the end of the day. This signals the onset of sleep. In fact melatonin is very interesting hormone, it’s an antioxidant that has a wide range of chemical function. This is independent of the sleep function itself a process that decreases oxidation by putting on the breaks on metabolism and slowing energy generation down. As a governor of sleep onset and also quality it stands between you and a lot of the problems mention above as well as supporting repair and recovery.

Melatonin production increases as light temperature (colour/wavelength spread) and intensity changes. The amount of blue light drops at the end of the day, things become a little more … orange. Flip-reverse this and you find that exposing people to blue light before bed decreases their melatonin levels and can mess with sleep onset.


After Bedtime

Unlit bathroom trips

The same holds true for nocturnal trips to the loo as it does for light before bed. Try and stay in the dark or near dark and turning on a light will disturb sleep patterns. And, no, don’t check your email.

Recording thoughts

In today’s world after lights out is often the time that the mind clears and important ideas pop into your head. You might want to keep a large pad and a pencil within easy reach, this way you can scribble the thought down in large writing in the dark.

The Environment

The bedroom environment should be


The bed’s mattress duvet and pillows should all be clean and fit for purpose. Studies clearly show that when your sleeping partner stirs of fidgets then usually so will you soon after so get as big a bed as possible. Pillows should be replaced every few years at the outside.

Try and have an adjustable duvet, or a selection of covers for warmer and cooler months.


The air temperature should be a few degrees cooler than you would have your lounge and the room should have ventilation. This for most people is about 17-19 degrees centigrade


Sleep cycles are dictated to a large extent by light so make sure you allow for deep sleep by shutting out as much light as possible. There’s some interesting research that suggests that your eyes aren’t the only features that can detect light, this means a eye mask is good but not enough. Keeping the room dark avoids that light toxicity problem and also avoids the inconvenience of a eye mask.


This one is obvious. Environmental stimuli will disturb sleep so take a good look at this. White noise generators exist that help by generating a type of sound that covers up all sorts of extraneous noise and which your mind then ‘tunes’ out.

Also, is there a TV in your bedroom?

Get rid of it.

Research clearly demonstrates a link between having a TV in the bedroom and decreased sleep duration. Also couples who have a TV in the bedroom generally had sex more often. Leave the TV in the lounge.

 In Part Three …

So what do you do what all this doesn’t work? In part three of this monster we’ll look at the ways to trouble shoot sleep, the gadgets and supplements out there that might help and what to do if your sleep, or rather lack of it, is becoming a real problem … 

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