An increasing number of us are regularly struggling to get enough sleep - which could be having negative consequences on our physical and mental health.
A recent international survey has reported that only around 46% of those surveyed were satisfied with their sleep, with participants reporting an average of 6.8 hours sleep per night during the week. Although there are no official recommendations when it comes to sleep, for adults, a minimum of 7 hours is suggested for optimal physical and mental wellbeing.
Sleep can impact food choices and metabolism
Reduced sleep duration can impact our food choices and disrupt metabolic processes, increasing risk of lifestyle diseases including cardiovascular disease, hypertension, diabetes and obesity. Research on the effects of sleep deprivation has found that even partial sleep deprivation can lead to increased energy intake (ie. calories/kilojoules), as our levels of satiety and hunger hormones (leptin and ghrelin) are disrupted, and we tend to snack more and choose foods that are higher in fat and sugar. There was no effect however on energy expenditure, meaning that the excess energy we consume may be stored and promote increased body weight.
Our bodies have an internal clock that regulates processes including metabolism and digestion of nutrients from food that we consume, and dysregulation of this process is thought to have negative health consequences. This is often seen in people who regularly work at night: light exposure and eating at night may disrupt our circadian rhythm and lead to adverse effects on metabolism and weight.
Some studies have found associations between short sleep duration and lower levels of certain nutrients, however there's still limited evidence here, and it's unclear whether this is an effect of sleep, or if a poor diet may be contributing to reduced sleep quality.
Diet may also impact sleep quality
Skipping breakfast, having an irregular eating pattern or a high intake of fat or sugary foods, or a low intake of fruit, vegetables or fish have all been associated with poor sleep quality. Following a Mediterranean dietary pattern has also been associated with reduced insomnia in women. Several studies have looked into the potential for certain foods to promote good sleep quality, and although there have been associations with several foods including milk, kiwifruit and cherry, evidence is limited, however there is more evidence that higher intakes of good quality carbohydrates may improve sleep quality.
Sleep and Mental Health
Sleep is also vital for optimal cognitive function and mental wellbeing, although as with diet, this is a two-way relationship, so mental illness can also impact your sleep quality. Getting enough sleep can help with mental and emotional resilience, as sleep helps the brain process emotional information. Diet can also play an important role here, as research has shown the Mediterranean diet in particular can have a positive effect on symptoms of mental illness.
Tips to help you improve sleep quality and get more sleep
Although getting enough sleep may sometimes be out of your control (if, for example you have small children or work nights), but these tips may help you improve your sleep quality:
Limit caffeine: caffeine can impact sleep if you’re consuming large quantities and/or late in the day - reduce your total intake and try to limit consumption to the morning.
Ensure you’re getting enough zinc, magnesium, vitamin B6, omega-3 fatty acids and tryptophan - these nutrients can help support good quality sleep. Eating a varied diet of minimally-processed foods from all foods groups helps you cover most nutrients.
Implement a bedtime routine to wind down and prepare for sleep. Dim lights and avoid using backlit devices (phones, computers, tv etc) for at least 1hr before bed, as this can interrupt production of melatonin (the sleep hormone).
Incorporate relaxing activities into your routine, even if you only have 10-15 minutes. This could be yoga, tai chi, meditation, deep breathing exercises, even reading or journalling.
If a busy mind impacts your sleep, keep a pen + pad beside your bed to write down any niggling thoughts before bedtime or if you wake in the night.
A sleep sounds app could help if you have trouble drifting off. There are many available - my favourite is Better Sleep.
If you’re still having problems sleeping, or still don’t wake up feeling refreshed, it may be helpful to talk to your doctor to check for any underlying conditions that may be impacting your sleep.