For many of us our sleeping patterns have been disrupted throughout the past year, as we adapt to flexible working and more screen time for leisure.
However, a lack of good quality sleep can sabotage any weight loss attempt and ruin the immune system, with those who have less than five hours per night being four times as likely to catch a cold than those who get a healthy eight hours.
Tamara Willner who lives in London, is a qualified nutritionist with an NHS-backed healthy eating plan and shares her health advice on Second Nature.
To mark World Sleep Day, she’s revealed the factors to consider when assessing your need for sleeo, saying: ‘On average, teenagers need about 8-10 hours of good quality sleep, whilst adults need about 7-9 hours. A common myth is that we need less sleep the older we get as adults.’
Here, Tamara reveals the simple trick that will help you calculate exactly how much rest you should be getting, insisting that everyone’s need will be different.
Tamara Willner who lives in London, has revealed the precise amount of sleep for optimal health varies depending on the individual (file image)
How much sleep do we need for our age?
Tamara revealed we spend one-third of our lives sleeping and the longest a human has ever gone without sleep is 11 days.
‘It’s important to note that the precise amount of sleep that we each need varies as we’re all unique,’ she said. ‘For example, the amount one adult needs will be different from the amount another adult of the same age needs.
‘Sleep experts note that we need just as much sleep in our 50s, 60s, 70s, and 80s as we do when we’re younger adults. However, as we age our brains are less capable of giving us that deep sleep and our sleep becomes more fragmented (more bathroom trips, aches or pains etc), which results in less sleep overall.
‘To figure out the right amount of sleep for you, try this exercise the next time you’re able to take an extended period of time off work, of two weeks at least (which is more challenging for those of us with children!).
‘Use the first week to unwind and the second week to sleep uninterrupted each night until you wake up. Taking an average of how many hours you sleep in that second week will give you a good idea of how much sleep is ideal for your body.’
Why not getting enough good quality sleep can prevent you from losing weight
Tamara explained that scientists are starting to better understand why poor sleep results in weight gain, as many people experience stronger food cravings and less willpower to resist unhealthy snacks after having a miserable night’s sleep.
Tamara said: ‘A recent scientific study showed that, when people had at least 8.5 hours of sleep, the part of their brain that controls feeding and appetite had a very low level of activation.
‘They were less hungry, had a lower energy intake, and lower activation of their reward and addiction systems in their brain.
Tamara cites a study that found metabolic rates of healthy participants declined after total sleep deprivation (file image)
‘When the scientists reduced the participants’ sleep to 4.5 hours, participants reported increases in hunger and appetite. In addition, they were more likely to choose snacks with 50 per cent more calories than people with 8.5 hours of sleep.
‘Finally, the sleep-deprived people were unable to resist snacks such as cookies, ice cream, and crisps, even though they had consumed a large meal two hours beforehand.
Tamara’s easy tips on how to achieve a better night’s sleep
1) Limit screen time 1 hour before bed
Our bodies have an internal ‘clock’ in the brain, which regulates our circadian rhythm. Mobiles, laptops and TVs emit blue light, which sends signals to our brain to keep us awake.
2) Address your ‘racing mind’
Take 5-10 minutes before you go to sleep to sit with a notebook and write down a list of anything that you need to do the following day.
3) Avoid caffeine after 12pm
If you want a hot drink in the afternoon or evening, go for a decaffeinated tea or coffee.
4) Keep a cool bedroom temperature
Keep bedroom thermostats to around 18°C. During spring/summer try sleeping with your bedroom window open to reduce the temperature and increase ventilation.
5) Limit alcohol in the evenings
While you might initially fall into deep sleep more easily, you then wake up frequently during the night and have poorer deep sleep overall.
6) Supplement vitamin D
Vitamin D plays a role in sleep. Vitamin D is widely available online and from most pharmacies. If you are unsure if this is appropriate or how much you need, please seek advice from your GP.
7) Ensure sufficient intake of magnesium and zinc
Foods high in magnesium include spinach, kale, avocado, bananas, cashews, and seeds. Foods high in zinc include meat, oysters, crab, cheese, cooked lentils, and dark chocolate (70%+).
‘On top of this, research has shown that sleep loss decreases how much energy our bodies use up in two ways. First, and more intuitively, physical activity significantly decreases on the day following sleep deprivation.
‘Secondly, a study demonstrated that after total sleep deprivation, metabolic rates of healthy participants declined, which led to less energy expenditure.
‘The combined effect of increased energy intake and decreased energy expenditure demonstrates how a lack of sleep could facilitate weight gain or prevent weight loss.’
Tamara explained sleep also effects our immune system, saying: ‘When we sleep our body goes into ‘immune stimulation’ mode. During this process, our immune system army restocks, and we can fight infection better.
‘On the flip side, being sleep deprived can stress our immune system. Evidence suggests that those who’re only sleeping five hours per night are four times as likely to catch a cold than those who get a healthy eight hours.
‘One fascinating study suggested that just one night of sleep deprivation in healthy people results in a 70 per cent drop in natural killer cells. Natural killer cells are like immune assassins that attack cancer cells, which naturally appear in your body every day, and fight infection.
‘So, we need an adequate amount of sleep to support our immune system in fighting regular infections and, on top of this, emerging evidence suggests that consistently getting enough good quality sleep can reduce our chances of developing chronic diseases, like Alzheimer’s, type 2 diabetes, and heart disease.
‘Not only does sleep affect our physical health, but it also has a huge impact on our mental health. Interestingly, there’s no psychiatric condition out there where sleep is undisturbed.
‘When we look inside our brains, using fMRI scans, even healthy people who’re deprived of just one night of sleep demonstrate a 60 per cent increase in reactivity in the area of our brain that generates strong emotions, called the amygdala.
‘As well as emotional stability, research suggests that our social skills suffer from sleep deprivation. A study demonstrated that emotional empathy (our ability to recognise and respond to other peoples’ emotions) significantly decreases after sleep restriction. The result is that we might struggle to feel sympathy and compassion when we’re overtired, which explains why we can be cranky or have a short fuse after a bad night.’