We spend about a third of our lives asleep, originally thought to be a passive activity, studies now show that when we’re asleep, our brain is engaged in a number of activities that have important implications for our health and wellbeing. This means sleep isn’t the absence of wakefulness, but an active and metabolically different state. As such, it needs to carry equal standing alongside balanced nutrition and adequate exercise as essential components for achieving and maintaining good health.
While adequate sleep in hours is essential for wellbeing, the quality and regularity of that sleep is often more important for overall health, longevity and reduced illness.
So how much sleep do we need? Most adults need 7-9 hours a night, but your ideal amount depends on age, lifestyle and how you feel during the day. Here’s how to work out what’s right for you.
Discover our full range of health benefit guides, including how to sleep better, how to wake up early in the morning and how to get to sleep.
What is sleep?
There are two main types of sleep that our brains cycle through: REM (rapid eye movement) and non-REM sleep. First, we’ll enter non-REM sleep, which typically involves four stages: the first occurs just as we doze off, the second is light sleep (when our body temperature drops and our breathing and heart rate regulate) and the third and fourth involve deep sleep. The majority of stages three and four takes place during the first third of the night, making the time you go to bed a really important factor for getting a good night’s rest.
Although we originally believed REM sleep, which occurs after stage four, to be the most important, research now suggests that the early stages of sleep are just as essential for learning, memory, restoration and repair. As we cycle into REM sleep, our eyes start to move rapidly behind our eyelids, and brain waves are similar to those when we are awake. Our breath rate increases and our body will become temporarily paralysed as we dream – if you wake during REM sleep, you’re 80 per cent more likely to vividly recollect your dreams.
Sleep cycles repeat about four or five times during the night, but with progressively less time spent in the initial sleep stages and more time spent in REM sleep. If your night is fragmented and you wake often, waking up between these sleep cycles feels easier because this is when you are in a lighter sleep. If you wake during deep sleep, you’re likely to feel more groggy and less refreshed. Sleep experts agree that these brief awakenings during the night are normal and occur as the body shifts from REM to light stage sleep.
Why is sleep important?
If you’ve ever risen after a poor night’s sleep, you’ll be well aware of how it makes you feel: tired, irritable and with a less-than-clear-thinking brain. Getting a good night’s sleep is important to energise us through the following day, but also for our brain to work well as well as to process what happens to us.
A good night’s sleep improves our brain’s ability to adapt to inputs – it helps us learn better, process memories more accurately, develop young brains and perform biological ‘housekeeping’ tasks like clearing our brain’s waste products more efficiently.
That said, a good night’s sleep doesn’t just impact how we learn and remember, it also has important consequences for our immune function, metabolism and hormonal balance. Poor sleep can make us more prone to infection and illness, disrupt our blood sugar balance and lead to high blood pressure, increase depressive states and make headaches and migraines worse.
The stages of deep sleep are especially important, because they enable the brain to process and file memories, deal with anxiety and initiate repair and restoration. Failure to do so has been associated with conditions like post-traumatic stress disorder.
If this sounds like you…
If your sleep issues are affecting your daily life and you’ve tried all the self-help measures available to you, Nutritionist, Kerry Torrens suggests that you refer to your GP for advice especially where:
- You’ve been experiencing sleep issues for 3-4 weeks or longer,
- Your poor sleep makes it hard to cope with daily tasks including work or school commitments,
- You feel constantly tired, irritable or have difficulty concentrating,
- You fall asleep unintentionally during the day,
- You have symptoms of sleep apnoea, including snoring, breathing pauses during sleep or gasping,
- You regularly rely on sleep medication.
How much sleep do I need?
How much sleep each of us needs depends on our own unique characteristics – including gender, genes, life stage – as well as environmental and behavioural factors. The following are guidelines and relevant for healthy individuals who do not suffer from a sleep disorder.
Children (three to five years): 10-13 hours regularly per night
For optimal health and to meet development needs, young children need to sleep for 10-13 hours – this includes daytime naps.
Children (six to 13 years): 9-12 hours regularly per night
Helping your child reach their guideline number of hours on a regular basis is associated with better outcomes, including improved attention, behaviour, learning, memory and emotional regulation. This may be partly explained by the fact that younger children spend a greater length of time in the deep sleep stages three and four.
Adolescents (14-17 years): 8-10 hours regularly per night
This group is one that is at risk of sleep deficits, that’s because they are more likely to be exposed to artificial light in the hours preceding bed; this, combined with the hormonal shifts of puberty, may predispose them towards an evening chronotype, making them less likely to benefit from morning daylight and the positive influences that has on circadian rhythms. Add to this the demands of a school timetable, and it’s easy to see how sleep deficits can arise. Sticking rigidly to a fixed bedtime, although likely to be unpopular, will support REM sleep.
Young adults (18-25 years): 7-9 hours regularly per night
Younger adults, similar to adolescents, may require more sleep, especially if they are recovering from sleep debt. They too may be influenced by late-night use of electronics, lack of physical activity and over-consumption of caffeine.
Adults (25-65 years): 7-8.5 hours regularly per night
Adults have the additional demands of work worries, social commitments and family dynamics to contend with – all of these may influence their ability to fall asleep and stay asleep. During our younger adulthood, fragmented sleep often involves waking from REM sleep; this tendency protects the important deep sleep stages. However, this protective mechanism declines with age, resulting in disturbances to non-REM sleep, too.
Older adults (from 65 years): 7-8.5 hours, regularly per night
As age increases, we find it harder to fall asleep and stay asleep. At this life stage, we may also experience a circadian shift towards a morning chronotype, which means earlier bed and rise times. For the elderly, sleep duration may appear good, but it tends to be sleep quality that is affected by frequent waking.
How to tell if you’re getting enough sleep
- Morning alertness: Do you wake up feeling energised or sluggish?
- Mid-afternoon dip: If you find you’re often feeling tired in the mid afternoon, despite eating balanced meals and snacking healthily, you may not be having enough sleep, or poor quality sleep
- Weekend lie-ins: You may be burning out from insufficient sleep during the week if you’re often craving lie ins at the weekend
- Reliance on caffeine: How much tea and coffee are you drinking? An over-reliance on caffeinated drinks to pick you up each day may be a sign you’re not getting enough sleep at night
- Mood stability: Insufficient sleep can lead to irritability and emotional reactivity. Over the long term, chronic sleep issues increase the risk of developing clinical depression or anxiety
Is quality sleep more important than quantity?
Although we tend to focus on the amount of time we perceive we’ve been asleep, there are other relevant factors that determine how beneficial our sleep may be. By asking yourself the following questions you may help clarify just how restful your sleep is:
- Efficiency – how much of the time in bed do you actually spend asleep?
- Timing – are your bedtime and wake times appropriate to allow you to reach your recommended sleep time?
- Consistency – is there any variability to your sleep from night to night?
- Satisfaction – how rested and restored do you feel next morning?
In addition to this, your sleep quality will be dependent on adequately completing the required cycles and stages of sleep; this requires your brain to consolidate and organise the cycles satisfactorily across the night.
What to try first if you’re not sleeping well
- Plan a consistent bedtime each night to get your body clock into a rhythm
- Try light exposure in the mornings to help work with your circadian rhythm, your body’s internal body clock that regulates sleep cycles
- Cut out caffeine before bedtime and monitor how your daytime drinking affects your energy levels and sleepiness
- Create a wind-down routine: Switching off screens, reading a book and turning on mood lighting can help
- Create a bedroom environment that is sleep inducing: is your bedroom too hot or too cold? Do you find having a tidy bedroom conducive to sleep?
What are the downsides of getting too little or too much sleep?
Sleeping less than seven hours regularly each night is associated with weight gain, obesity, type 2 diabetes, heart disease, stroke and depression. It’s also likely to increase our chances of illness, put us at greater risk of accidents, heighten the sensation of pain and result in poor physical and mental performance. This applies to children and young adults too; they are likely to experience decreased glucose tolerance and insulin sensitivity, increased evening cortisol and disruptions to the hormones (ghrelin and leptin) that control appetite.
Growth hormone is released around the clock, but it is at night that it peaks, typically during the first 90 minutes of sleep. If we stay up late and delay sleep, we don’t experience the growth hormone peak that night – if we do this on a consistent basis, it may affect growth and development and result in decreased muscle mass and exercise capacity.
Short-term effects (1-7 days) of too little sleep:
- Reduced concentration and focus,
- More likely to make mistakes or have an accident,
- Mood swings and irritability,
- Appetite changes and sugar cravings.
Longer term effects of missing sleep (weeks to months):
- Elevations in blood pressure and other cardiac and inflammatory markers,
- Impaired metabolic health including blood sugar control,
- Increase in weight and lethargy,
- Reduction in muscle mass and exercise capacity.
Sleeping too much can also be damaging to your health, being associated with psychiatric illness, higher body mass index (BMI) and an increased risk of cardiovascular disease.
Shift workers, parents and poor sleepers
Achieving a refreshing rest when working shifts, raising children or suffering from chronic insomnia often requires a degree of resourcefulness. This may involve grabbing power naps during the day, anchoring a consistent sleep window into your routine and optimising micro wind-downs to help you rest at times that suit you and your commitments. While implementing these strategies always keep in mind the basics – keep your sleep environment cool and dark, avoid sleep disruptors such as caffeine, sugar and alcohol and minimise phone or tablet use at least 30 minutes before your rest.
Your questions answered…
Is a sleep tracker helpful?
Fitness trackers and smartphone apps are increasingly popular – they assess sleep duration and, in some cases, sleep quality. The algorithms used on these devices are proprietary, and evidence suggests in some cases they may underestimate sleep disruptions and overestimate sleep duration and quality. That said, many users find them helpful because they highlight the importance of sleep and provide some form of indicative measure, although more guidance is needed as to how the information they collect may effectively be used.
Are blue light-blocking glasses a worthwhile investment?
These glasses contain lenses designed to reduce the amount of blue light that reaches the eye. Some advocate that by reducing blue light during the evening, you may promote restful sleep. While the lenses, which typically have a yellowish tint to them, are effective at filtering blue light rays, there is limited scientific evidence to support their use for the improvement of sleep.
Can you catch up on sleep?
You can partially catch up on sleep by napping during the day or lying in at the weekends, this may help immediate concerns over poor sleep such as helping you think more clearly. However, if your sleep issues are chronic and long standing these ‘catchups’ will not bring about a full recovery of your sleep debt. So, while you may feel a temporary relief, this approach will not fix the metabolic changes or long-term health effects caused by chronic sleep deficits.
Is 6 hours ever enough?
Most research in this area agrees that six hours of sleep is typically not enough for the majority of adults, with at least seven hours of sleep every night, cited as the recommended amount for optimal health.
Do women need more sleep than men?
Yes, research suggests that in general women need more sleep than men. This is due to hormonal fluctuations, a greater risk of insomnia and increased brain activity from multi-tasking.
Can you oversleep?
Yes, known as hypersomnia, this is when someone may consistently sleep for 9-10 hours per night. Regular oversleeping is also linked to adverse health effects including depression, diabetes, heart disease and increased mortality risks.
Tips for a quality night of sleep
Creating the right environment and easing yourself towards restful sleep may make all the difference. Follow these tips to promote a relaxing night:
- Try some sleep supportive foods
- Have a warm bath leading up to (but not immediately before) bedtime – sleep is accompanied by a decrease in core body temperature, and warming up in the hours before bed appears to help promote sleep and improve its depth
- Make your bedroom a quiet and relaxing space, and keep the room temperature at a comfortable level
- Set a bedtime that is early enough for you to enjoy your recommended hours of sleep
- What you wear in bed influences both how quickly you fall asleep and how deep the sleep you enjoy – at cooler temperatures (17C), wool nightwear works best, while at hotter room temperatures (22C), consider cotton
For more tips, check out our guide on improving sleep hygiene and for those who regularly experience problems check to determine whether your symptoms are classed as insomnia.
So, how much sleep do you need?
Sadly, there’s no magic number for the ideal duration of sleep – it depends on many factors unique to each and every one of us. Plus, a truly restorative slumber involves smoothly transitioning through the sleep cycles. This means the best measure has to be the amount of sleep that allows you to wake refreshed, well-rested and able to perform at your best the following day.
Nutritionist, Kerry Torrens recommends focusing on sleep patterns over perfection, with a regular wake-sleep routine being a key component to consistent, restorative sleep. If your sleep issues persistent and disrupt your ability to function or cause you concern, seek the advice and guidance of your GP.
A simple way to reset this week
Try this daily checklist over the next seven days and review your sleep quality at the end of the week:
- Have you audited your caffeine intake during the day and reduced your drinking or switched to non-caffeinated options before bedtime?
- Have you created a wind-down routine you enjoy?
- Have you created an inviting bedroom environment free from distractions that makes you want to sleep?
- Have you set a fixed wake time each day?
- Are you opening your curtains when you wake to benefit from natural light exposure?
Now read:
The best sleep trackers reviewed
10 top tips to support your child’s sleep
8 late night snacks for a healthier bedtime
Why am I always tired?
5 reasons you’re waking up tired with no energy
Best sleep supplements
Best sleep trackers
Best sleep earplugs
Do you have trouble sleeping? What helps you nod off? Let us know in the comments below.
This page was reviewed on 30 April 2026 by Kerry Torrens.
All health content on goodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.
