Sleep. Our best friend.
As a 30 year old woman, sleep is one of my favourite things. I don’t enjoy super late nights or partying. But, as a 30 year old woman with a business and full-time job, and as someone with a pretty intense hobby most of the year, sleep can sometimes be negated for more ‘productive’ activities – yes, standing in my bikini scrutinising my hamstrings is so productive, I don’t know what you mean. Thankfully, my body loves sleep. From the second I hit my pillow, despite the intention to visualise my future successes (current favourites include lying on the beach in Bali, travelling LA and learning all the new mindfulness approaches), I am asleep within approximately 3.4 minutes and generally gone until 5am. My FitBit tells me that although my actual duration of sleep isn’t the best, that in general, my time spent in ‘deep sleep’ and ‘REM’ (the good stuff), is above average. So I’ll take that (always have been relatively happy coasting along above average…). However, there are certain times when sleep can become a bit of an issue. When I’m super lean and super hungry, sleep can be disturbed and I can struggle with getting enough rest. More importantly, so many of my clients are amongst the many thousands of people in the UK that suffer with restlessness in the night, and lack of sleep. Other than making us miserable people to be around, what impact does this have in terms of our body composition, performance and nutrition? Why does it matter? *Disclaimer, I may have written this piece to provide evidence to the other half for why exactly it is that I have to go to bed at 9pm, and why exactly I’m allowed to be grumpy when he keeps me up past 10…*.
Why do we need sleep?
We all know how rubbish we feel after less than our usual amount of sleep. It can be hard to concentrate, training can be a struggle and we can just feel generally fatigued. But how does it affect our nutrition?
You may have heard (or even noticed for yourself) that a lack of sleep can make you feel hungrier than usual (ravenous ok, it makes me ravenous). And physiologically, there is a reason for this. Two key hormones involved in regulation of food intake, named leptin and ghrelin (the latter being the one that makes your tummy grumble) are influenced by sleep quality and/or duration. Leptin (the hormone that reduces food intake) decreases with sleep deprivation, whilst ghrelin (which stimulates appetite) is increased with sleep deprivation. Reduced sleep can also increase cortisol (the stress hormone) and inflammatory responses in our bodies, not ideal when trying to recover from stressful exercise that already induces an inflammatory response (DOMS for days anyone?). Lack of sleep can also influence the way that we break down blood sugars (blood glucose metabolism) which can influence our risk of health problems such as diabetes and obesity. And, potentially of more importance to you right now, can actually influence protein synthesis (building and recovery of muscle) i.e. difficulty in making the gains!
So many of you will prioritise inhaling protein after training, consuming supplements that you think can enhance recovery and/or minimise muscle breakdown (BCAAs, glutamine, etc.). You spend £100s on this stuff, freak out when you forget them (one of my first dates with my boyfriend involved near tears at a BCAA breakdown) and swear by their abilities to reduce DOMS, improve muscle mass etc. etc. etc. So many of you glorify ‘the grind’, shout about being part of #TeamNoSleep and generally, seem to lack much conscious effort to improve on your sleep. But when sleep is so crucial to our appetite, and therefore body composition, performance in training and last (but definitely not least) our brain power, why are we not prioritising something so simple, cheap and effective?
Nutrition and sleep
So many of my clients suffer with lack of sleep, some of which has an obvious origin, and others who have naturally always struggled to get their full 40 winks. So what can we do to improve sleep quality or time? And what can actually make it worse?
Those of you who have ever maintained any sort of fat loss diet for a prolonged period, may have experienced a lack of sleep quality. Going to sleep hungry, waking up hungry, interrupted sleep patterns. Low calorie diets can negatively impact sleep. Eat more food then fools! Seems like a logical solution. But what if you don’t want to stray from your goals of fat loss?
Pre-workouts, coffee, Monster (Monster white anyone?), fat burners, caffeine tablets, the list goes on. Working an 8/10/12 hour day then hitting the gym for training may well require some assistance from our favourite stimulants. But consuming these late at night can lead to prolonged time to sleep (sleep onset latency).
HIGH FAT DIETS
IT may also be that chronicaly high fat intakes i.e. high fat diets (FYI those of you that love the keto life), can negatively influence sleep. At least when monitoring current nutritional intakes in older women, the only notable relationship was between total fat intake and reduced sleep time. Even if we ignore the limitation of assessing current intakes using a food frequency questionnaire, other such research supports the notion that high fat (>50% of intake from fat) appears relatively less beneficial compared to carbohydrate and fat diets. This is especially apparent if we consume fat close to bed time.
So, if you’re dieting and dieting on a somewhat low-carb, high-fat diet, not only do I salute you (my carbs are my comfort clearly), but you may be at greater risk of sleep deprivation or indeed, you may well be reading this with a grumbling tummy, falling in to your sugar-free Monster whilst struggling to remember what you just read (FYI, it was that low calories suck for sleep).
So what can we do to help ourselves?
I have summarised somewhat artistically, methods that I as a Nutritionist, implement with clients who struggle to sleep well. Most of these can be implemented through consumption and timing of whole foods, but there are also a number of supplements that may be useful.
Oh carby carbs, oh how we love you. Carbohydrates can positively impact on our sleep and, what may seem strange, high GI carbohydrates (when consumed more than 1 hour before bed), may improve the time it takes for us to get to sleep.
Protein may improve sleep quality through reducing the amount of time you wake up. You know your best friend the FitBit, when it tells you your time awake? It may be that greater amounts of protein can reduce that time awake.
Tryptophan is an amino acid that is transported in to the brain and is the precursor for serotonin (promotes sleep and mood balance) and melatonin (promotes sleep). Increasing tryptophan can increase serotonin and melatonin, enhancing sleep. Foods containing relatively large amounts of tryptophan include turkey, watermelon, oats, nuts, seeds (e.g. sunflower) and legumes. You can also buy it as a supplement.
Carbohydrates likely help sleep through this mechanism. Carbohydrates stimulate the release of insulin, which not only increases carbohydrate uptake but also increases amino acid uptake. These amino acids compete with tryptophan to cross in to the brain, so the more of them we have, the less of tryptophan in the brain and therefore the less serotonin. If insulin stimulates uptake of these other amino acids in to other tissues, there is more free tryptophan relatively speaking, to get in to the brain. So carbohydrates allow more tryptophan to cross in to the brain and produce more sleep friendly hormones!
Although debated, melatonin may enhance sleep quality in some cases. It can be found in tart cherry juice, which has been shown to improve sleep, although this may also be down to the antioxidant and anti-inflammatory properties of the juice. In general, vegetables, fruits and grains are useful sources of dietary melatonin. Some vitamins and minerals are required to activate production of melatonin such as Vitamin B, magnesium, zinc and polyunsaturated fatty acids, so these are also useful targets for nutritional intervention.
Valerian you say? No idea? Most don’t. Valerian is a herb that may help reduce anxiety and promote calmness, assisting in sleep promotion. It is found in many sleep supplements that you can buy over the counter, or can be purchased individually.
So go grab a delicious bowl of oats, stir in some whey protein and top with a sprinkle of your favourite fruit (tart cherries perhaps?) and toddle off to bed. And remember the rest, no phones, to TVs, get your favourite book for an hour or so after eating. Keep trying different strategies from the list above to see what works for you, everyone is different. And go get some sleep people!
Afaghi, A., O’connor, H. and Chow, C.M., 2007. High-glycemic-index carbohydrate meals shorten sleep onset. The American journal of clinical nutrition, 85(2), pp.426-430.
Crispim, C.A., Zimberg, I.Z., dos Reis, B.G., Diniz, R.M., Tufik, S. and de Mello, M.T., 2011. Relationship between food intake and sleep pattern in healthy individuals. J Clin Sleep Med, 7(6), pp.659-664.
Grandner, M.A., Kripke, D.F., Naidoo, N. and Langer, R.D., 2010. Relationships among dietary nutrients and subjective sleep, objective sleep, and napping in women. Sleep medicine, 11(2), pp.180-184.
Halson, S.L., 2014. Sleep in elite athletes and nutritional interventions to enhance sleep. Sports Medicine, 44(1), pp.13-23
Hindmarch, I., Rigney, U., Stanley, N., Quinlan, P., Rycroft, J. and Lane, J., 2000. A naturalistic investigation of the effects of day-long consumption of tea, coffee and water on alertness, sleep onset and sleep quality. Psychopharmacology, 149(3), pp.203-216.
Howatson, G., Bell, P.G., Tallent, J., Middleton, B., McHugh, M.P. and Ellis, J., 2012. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. European journal of nutrition, 51(8), pp.909-916.
Lindseth, G., Lindseth, P. and Thompson, M., 2013. Nutritional effects on sleep. Western journal of nursing research, 35(4), pp.497-513.