Diet and sleep: How nutrition can help combat an ‘epidemic of insufficient sleep’

Many of us, it turns out, are unlikely to be getting the recommended minimum amount of sleep. A recent study from healthcare provider Benenden Health found 68% of adults in the UK are failing to get a straight seven-hours shuteye, with the nightly average sitting at just six hours. “Our research has highlighted an epidemic of insufficient sleep across the UK,”​ reflected Matron at Benenden Health Cheryl Lythgoe, pointing to the negative impact not getting enough sleep can have on our mental and physical wellbeing.

Data from the British Nutrition Foundation shows this issue isn’t confined to the adult population. A survey conducted by the BNF found 43% of adults report they didn’t sleep for the recommended seven-hours the night before. Concerningly, this trend was also true for children, with 32% of primary-aged children and 70% of secondary school pupils reporting that they weren’t getting nine hours sleep a night. On top of this, 80% of adults and 44% of secondary school children reported waking up at least once during the previous night.

Poor sleep linked to poor health

A strong body of research links poor sleep to a host of health issues. “The connections between insufficient sleep and adverse health are independent of energy intake and physical activity levels, indicating that sleep itself is important,”​ according to Jesús Martínez Gómez, a researcher in training at the Cardiovascular Health and Imaging Laboratory at the Spanish National Centre for Cardiovascular Research (CNIC). Addressing the European Society of Cardiology (ESC) Congress earlier this year, Martínez Gómez presented the findings of his work linking problematic sleep to an increased likelihood of being overweight or obese among teens.

Martínez Gómez highlighted a strong link between weight and sleep. Compared with optimal sleepers, overweight or obesity was 21% and 72% more likely in very short sleepers at 12 and 14 years, respectively. Short sleepers were 19% and 29% more likely to be overweight or obese compared with optimal sleepers at 12 and 14 years. Similarly, both very short and short sleepers had higher average metabolic syndrome scores at 12 and 14 years compared with optimal sleepers. “Our study shows that most teenagers do not get enough sleep and this is connected with excess weight and characteristics that promote weight gain, potentially setting them up for future problems,”​ Martínez Gómez warned.

In adult life, this can translate to a higher risk of obesity and related NCDs like type 2 diabetes and heart disease. Further research presented at the ESC Conference 2022 suggested that as many as nine-in-ten people have ‘suboptimal’ sleeping patterns that, the researchers said, are associated with a higher likelihood of heart disease and stroke. The scientists estimated that seven-in-ten of these cardiovascular conditions could be prevented if everyone was a 'good' sleeper.

“Our study illustrates the potential for sleeping well to preserve heart health and suggests that improving sleep is linked with lower risks of coronary heart disease and stroke. We also found that the vast majority of people have sleep difficulties,​” Dr. Aboubakari Nambiema of INSERM (the French National Institute of Health and Medical Research), commented. “Given that cardiovascular disease is the top cause of death worldwide, greater awareness is needed on the importance of good sleep for maintaining a healthy heart."​

Sleep quality changes what we eat and how we metabolise it

Why is poor sleep linked to increased weight and associated health conditions?

One contributory factor is that a lack of sleep alters the food that we crave and can have a negative impact on dietary choices, including higher intakes of calories and more frequent snacking on less healthy foods. Even mild sleep deprivation raises hunger levels and alters appetite hormones, pushing people towards higher calorie options. Some studies suggest sleep deprivation can alter our motivation and reward drivers, making unhealthy ‘comfort’ foods more appealing beforehand and more satiating after you’ve eaten them.

Research published in Experimental Physiology​ found wake/sleep cycles cause metabolic differences​ and alter our body’s preference for energy sources. The researchers discovered that people who stay up later have a reduced ability to use fat for energy, meaning fats may build-up in the body and increase risk for type 2 diabetes and cardiovascular disease.

These metabolic differences relate to how well people who stay up late versus those who rise early use insulin to promote glucose uptake by the cells for storage and energy use. People who prefer to be active in the morning rely more on fat as an energy source and are more active during the day with higher levels of aerobic fitness than people who are active in the night. “The differences in fat metabolism between ‘early birds’ and ‘night owls’ shows that our body’s circadian rhythm (wake/sleep cycle) could affect how our bodies use insulin. A sensitive or impaired ability to respond to the insulin hormone has major implications for our health,”​ explained senior author Professor Steven Malin of Rutgers University.

There is a risk that this connection between poor sleep and junk food cravings could create something of a vicious cycle because what we eat also has an effect on sleep quality and duration.

What to eat for a good night’s sleep

While factors from stress to blue light exposure all contribute to disrupted sleeping patterns, there are some clear dietary dos and don'ts. Stimulants like caffeine, for instance, cause your heart to race, increase alertness and can take hours to wear off - meaning consumption can have a big impact on how quickly you fall asleep. 

There is a long-held belief that warm milk will help you sleep and indeed whole milk is one of the largest sources of tryptophan, including 732 milligrams per quart. However, not all proteins sources are as helpful. The National Sleep Foundation suggests large meals and foods high in protein can keep you awake if eaten before bed because digestion slows at night. 

Perhaps more misunderstood is the connection between alcohol and sleep, with many people believing that a night cap can aide sleep. The BNF found nearly one-in-ten adults consume alcohol before bed. Around half (52%) who do so report falling asleep within 10 minutes, compared to 61% who don't consume alcohol. Alcohol also impacts sleep quality and nearly half of adults who drank alcohol before bed woke up two or more times during the night, compared to 38% of those who did not. While only 29% of all adults surveyed by the BNF agreed they felt ‘well-rested’ when they woke up, for those who drank alcohol before bed this figure was even lower at 20%.

Eating sugar can also be overstimulating, with one 2016 study concluding that people who had high-sugar diets tended to sleep less deeply​ and were more likely to wake up during the night. Researchers suggest that eating a diet that is high in sugar, saturated fat and processed carbohydrates can disrupt your sleep, while eating a diet that is generally accepted as healthier - more plants, fibre and foods rich in unsaturated fat - seems to have the opposite effect.

A study from the University of Michigan shows that fruit and veg consumption could help with insomnia​. Mixed berries are ‘particularly’ beneficial to sleep, according to industry group British Berry Growers. Raspberries are rich in melatonin – the hormone that regulates our sleep-wake cycle – and blueberries are a source of tryptophan, an essential amino acid that helps to produce melatonin.

What other ingredients and innovations are meeting this need?

To date, there are no approved health claims about nutrition and sleep. Nevertheless, there are a number of ingredients that are popularly associated with improved sleep.

This connection can be noted in recent product launches like OHMG Magnesium Water, which claims to be the world’s first drink containing three types of magnesium. OHMG links its beverage with health benefits including ‘tiredness and fatigue’ as well as ‘improved sleep’.

Horlicks, meanwhile, has taken a more traditionalist approach to tapping the sleep aid market through a new line of Blends shakes. It is fortifying the Healthy Sleep SKU with vitamins B12, B6 and C – all of which it says are associated with ‘reduced tiredness’ – while also including traditional herbal remedies chamomile and valerian into its formulations.

Elsewhere, CBD has proven a trendy hit with consumers seeking that elusive good night’s sleep, as evidenced by the onslaught of ‘relaxation’ drinks and snacks containing the ingredient. Goodrays is one such innovator hitting the shelves. The challenger brand has just secured a listing at the UK’s largest supermarket group, Tesco.

“Our mission is to make high-quality CBD accessible, mainstream and widely understood, and to have a listing in Tesco, the UK’s largest retailer, is genuinely a dream come true. It’s incredibly exciting to be supporting the next wave of innovation in functional drinks and it shows that the health benefits of CBD have begun to be more widely accepted,”​ Founder Eoin Keenan enthused.