Importance of getting enough sleep

Emma Brown - Nutritionist | 17 Jan, 2020

With our increasingly busy lifestyles, many of us try to get by on less sleep than is recommended – often people boast about the fact they can survive on 5 or so hours a night. But while we may be able function on minimal sleep, this can have a negative impact on our long term health and wellbeing.

Why we sleep

We know we need to sleep, as various studies have shown that a complete absence of it would ultimately result in death, but why exactly do we sleep? In truth, it's not fully understood why we need the amount we do, but we do know that while we rest our body does various important processes. It spends time repairing body tissue and releasing immune boosting chemicals. Sleep is also essential for our brain to process and store memories – in fact this is potentially one of the most important reasons for sleeping, it gives our brain time to process all the information that's been thrown at it throughout the day.

effects of low sleep

Effects of lack of sleep

If we miss the odd night's sleep or have an occaisonal bad night, it's not a biggy. But if we continuously get an inadequate amount of sleep, the long term effects can be quite alarming!

  1. Fatigue – regularly failing to get adequate sleep leaves us feeling sluggish and unmotivated to do things we normally would. This can affect our overall happiness and wellbeing.
  2. Decreased immunity – sleep is important for maintaining a healthy immune system, so a lack of it can weaken our defences making us more susceptible to illness, such as colds.
  3. Increased risk of diabetes – research has shown that ongoing inadequate sleep can change the way our body manages blood sugar levels, ultimately leading to an increased risk of type 2 diabetes.
  4. Increased risk of heart disease – if we're regularly going without the right amount of sleep our heart rate can increase, along with our blood pressure, which can cause an increased risk of heart disease.
sleep and weight

Sleep and weight

So what about weight? There's certainly a link between a lack of sleep and weight gain, with people who get by on less sleep being more likely to be overweight. That said, sleep deprivation isn't thought to directly cause us to put on weight, but more that it results in behaviours that lead to weight gain. Plus the longer you are awake, the greater the 'eating window' - that is, time available to consume more calories.

A lack of sleep has been linked to impaired appetite control and an increased desire to eat. Long term, this could lead to continued overeating and weight gain.

Likewise, researchers found that when people have had a bad night's sleep, their energy expenditure the following day is reduced. It stands to reason that you'll be more likely to give the gym a miss if you're feeling tired.

Effects of too much sleep

Is it possible to sleep too much? Well interestingly, it is! Regularly sleeping more than 9 hours a night can have a negative impact just as not sleeping enough, potentially causing health concerns over time.

The ideal amount for most adults is 7-9 hours as recommended by the National Sleep Foundation. Sweet dreams!

Nutritionist Emma Brown (ANutr), MSc Human Nutrition is passionate about how food science applies to the human body, and how the nutrients in what we eat affect us and ultimately have an impact on our health.