Sleep is crucial to each and every one of us. When we are asleep, our body is ‘programmed’ to do much of the cell repair and regeneration required to keep us healthy. For some lucky individuals sleep comes easily, for others quality sleep is elusive.
There are numerous commonly cited reasons why consistently good sleep evades us: from a too warm bedroom, to nocturnal urbane noise, but let’s cut to the chase and look at how our weight and eating habits might affect our sleep.
The most obvious culprit is caffeine. Some people can drink a double espresso at 10pm and be asleep by 10.30pm, but for most of us caffeine is a stimulant that can stop us from falling asleep. It is worth noting that not only coffee contains caffeine; chocolate, fizzy drinks, energy drinks, green tea and even some decaf coffees contain caffeine.
Caffeine has a ‘half-life’ of 4-6 hours i.e. it takes an average 8–12 hours for the caffeine in a cup of coffee to be cleared from the body. For some people it might take less time, for others notably longer. If you are struggling to fall asleep at night, it is therefore advisable to avoid any caffeine after midday – to see if you notice a difference.
Being overweight can also impact on your sleep quality. Obstructive Sleep Apnea is a potentially serious condition, more commonly seen in overweight and obese individuals, which can go unnoticed (undiagnosed) for months and even years, although heavy snoring can be an indicator of the condition.
In sleep apnea the individual stops breathing, leaving the brain (and the rest of the body) lacking in oxygen; this can occur dozens of times during the course of the night leaving the individual waking up feeling unrested and with ‘morning headaches’. Mostly the brain senses the lack of oxygen and rouses the person momentarily who may then cough or change position to allow the airway to open. One proven way to reduce the complaint is to lose weight.
If you are prone to reflux (a burning sensation in the esophagus after eating), try to avoid eating large meals late into the evening, especially if they are spicy or high in fat like Indian curries and Mexican food as doing so can cause significant discomfort and inhibit the onset of sleep. Invariably it is best not to eat for a few hours before heading to bed if you want to ensure a good night’s sleep.
Your working or social life may mean that you often eat later in the evening; this can impact on your digestion, your glucose metabolism and your circadian rhythm* or sleep/wake cycle. These can all result in either finding it difficult to get comfortable and being able to fall asleep or causing your blood glucose to drop and your body reflex waking you up in the small hours – and finding it difficult to fall back to sleep again.
Poor blood glucose (sugar) control can affect your sleep and, vice versa, sleep can affect blood sugar levels. A lack of sleep has been shown to increase blood sugar levels. Over time, this can increase the risk of developing metabolic syndrome (a reversible pre-diabetic state) if coupled with other risk factors such as poor diet and poor lifestyle habits.
It might be prudent to have your blood glucose levels assessed (HbA1c) if you suspect your wakefulness could be associated with poor glucose metabolism.
Check-list: Does diabetes run in your family? Are you overweight? Have you lost weight recently, without trying? Do you find you are more than usually thirsty? Are you having to get up in the night to urinate? Are you feeling hungry, despite having eaten? Do you experience blurry vision? Are you feeling uncharacteristically fatigued?
An alcoholic ‘night cap’ might also sabotage sleep: If you drink alcohol before heading to bed, you may fall into a deep sleep quickly, but actually alcohol disrupts your sleep cycle. As the night goes on you spend more time in this deep sleep and less time in the more ‘restful’ REM sleep. Consequently, the next day you can be left feeling tired.
We are seeing a strong, though so far ‘unproven’, link between gut health and sleep. The science is still in the early stages and although an enormous amount is understood about the relationship between a lack of sleep and appetite, obesity and insulin resistance (disrupted blood glucose metabolism) the role of our gut microbiome with regard to how it improves our sleep is not yet understood.
We do know that chronic sleep deprivation increases our chances of obesity and how we ‘control’ our food intake. This is down to the decrease in the hormone that makes you feel ‘full’ (Leptin) and a surge in the ‘hungry’ hormone (Ghrelin). Researchers have calculated that a sleep deprived individual can consume as many as 300 calories more than ‘usual’ after a poor night’s sleep! Even if it is only 100 calories more a day, this can, over weeks and months of poor sleep, result in insidious weight gain.
We recognise that a lack of sleep affects the parts of the brain that is responsible for ‘impulse control’, which in turn can increase the chance of us making unhealthy food choices – which then impacts the gut adversely and perpetuates the sleepless/weight gain cycle.
Prescription sleeping tablets should be a last resort. However, there are some naturally occurring compounds that are available in supplement form that are proven to help us relax or feel calm; beneficial when we are heading to bed: It might be worth trying one or more of these, in your pursuit of improved sleep, while seeking the true reason for your poor sleep.
Valerian – a plant extract.
L-Theanine – an amino acid found in tea.
Inulin** – a plant sourced prebiotic fibre
Chamomile – a plant often used in teas and tinctures.
Lavender – as an essential oil.
If you should decide that you would like to take a ‘sleep aid’ it is advisable to consult your doctor, if you are taking any prescription medication, to make sure there are no interactions between your medication and the active compounds in the supplement.
Nutritionist MSc KCL.
RNutr.(Public Health). AMRSPH
Tamara is an experienced nutritionist with over twenty years’ in practice covering three continents.
She gained her MSc in Nutrition from Kings College London in 1994, long before ‘Nutrition’ was a buzz-word and the term ‘Super Food’ had been coined.
Early on in her career she devised company-wide healthy eating policies for blue-chip London-based clients including Morgan Grenfell and SmithKline-Beecham, before heading to the USA (after a six-month spell living in an African Zula reserve) to work with the US Marines.
Tamara has also worked as a volunteer in South Africa’s ‘townships’, establishing close relationships with Suto health practitioners through nutrition programmes, and in the Middle East, advising a teenage Olympic swimmer in the lead-up to the Olympic Games.
Her area of passion has always been the gut and its fundamental importance to our overall physical and mental health. With the increasing interest in research in the gut microbiome she believes that people are starting to ‘see the light’.
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