WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Sleep is a rare commodity for many Americans. While some deliberately miss out on sleep by staying up late to binge-watch their favorite TV shows and others are kept up due to financial worries, relationship problems and other forms of stress, many others lie awake in bed for reasons that are difficult to pinpoint.
Some people struggle with an inability to fall asleep and stay asleep for no apparent reason. If you fall into this category, it's a good idea to take stock of your diet, especially your intake of sugar-sweetened caffeinated drinks.
Lack of Sleep Linked to Consumption of Sugar-Sweetened Caffeinated Drinks
A new study led by University of California San Francisco (UCSF) scientists found people who slept five or fewer hours a night drank 21 percent more sugar-sweetened caffeinated beverages than people who slept a healthier seven to eight hours a night.
Those who slept six hours a night also drank more sugary beverages — 11 percent more — than people who slept longer. At this point, it's not known if the sugary, caffeinated drinks are keeping people awake or if the opposite holds true and lack of sleep drives people to reach for more soda and energy drinks.
The study noted, "Although caffeinated drinks could account for impaired sleep, it is possible that short sleep could influence one's appetitive drive for sugared caffeine drinks."1 Lead author Aric A. Prather, Ph.D., assistant professor of psychiatry at UCSF, stated in a press release:2
"We think there may be a positive feedback loop where sugary drinks and sleep loss reinforce one another, making it harder for people to eliminate their unhealthy sugar habit …
This data suggests that improving people's sleep could potentially help them break out of the cycle and cut down on their sugar intake, which we know to be linked to metabolic disease."
Lack of Sleep and Sugary Drinks: a Recipe for Metabolic Disease
Consumption of sugar-sweetened drinks has repeatedly been identified as a risk factor for metabolic diseases such as type 2 diabetes. A meta-analysis found that drinking one or more 250 ml (8.45 ounces) servings of soda per day raised the individual's risk of type 2 diabetes by 18 percent.3
Poor sleep is also known to have a significant bearing on metabolic disorders such as obesity, high blood pressure and type 2 diabetes. Previous research suggested that addressing your sleeping habits may be key for both the prevention and treatment of metabolic disease. As reported by Medical News Today:4
"The reason why metabolic disorders are so influenced by sleep patterns seems to be due to sleep influencing the body's ability to control food intake, metabolize glucose and maintain energy balance.
… disruption of the body's natural sleep cycle — as experienced by shift workers — has a pronounced link with suffering metabolic health, as well as rates of chronic illness and early death."
The link may be so ingrained that it appears even from birth. A separate study published in the International Journal of Obesity found that infants who sleep less eat more, which places them at increased risk of future obesity and related health problems.
Infants who, at the age of 16 months, slept less than 10 hours per day ate an average of 10 percent more calories than those who slept for at least 13 hours daily.5
Sleep Deprivation Makes You Eat More
If you've ever felt ravenous after a night of too little sleep, it's not your imagination. Research shows that sleeping for about four hours a night causes people to eat more — on average about 385 calories more — than they would after a longer night's sleep.6
There are many theories as to why skimping on sleep makes you eat more, including by increasing the "hunger hormone" ghrelin and decreasing the hormone leptin, which is involved in satiety.
Some researchers have also suggested that sleep deprivation may increase your desire to seek out food as a reward,7 which could also be the case with seeking out more sugary beverages, as noted in the featured study.
Lack of sleep is also associated with activation of your endocannabinoid system — the same one activated by marijuana. In essence, losing out on sleep gives you the "munchies."
In fact, without enough sleep your fat cells may become "metabolically groggy," according to Matthew Brady, Ph.D., an associate professor of medicine at the University of Chicago.
He co-authored a study that found after four nights of sleep deprivation (sleeping only 4.5 hours per night), study participants' insulin sensitivity was 16 percent lower, while their fat cells' insulin sensitivity was 30 percent lower, and rivaled levels seen in those with diabetes or obesity.8
Sleeping Better Could Help You Lose Weight, Prevent Disease
If you struggle with sugar and other carb cravings and find it difficult to stick with a healthy diet, improving your sleep hygiene and sleeping more could help you get on the right dietary, and weight loss, track.
The link between what you eat and how well you sleep, and vice versa, is continuing to be revealed but, already, distinct dietary patterns among short and long sleepers have been found. One study evaluating the diets and sleep patterns of more than 4,500 people found:9
- Very short sleepers (less than 5 hours a night): Had the least food variety, drank less water and consumed fewer total carbohydrates and lycopene (an antioxidant found in fruits and vegetables).
- Short sleepers (5-6 hours): Consumed the most calories but ate less vitamin C and selenium, and drank less water. Short sleepers tended to eat more lutein and zeaxanthin than other groups.
- Normal sleepers (7-8 hours): Had the most food variety in their diet, which is generally associated with a healthier way of eating.
- Long sleepers (9 or more hours): Consumed the least calories as well as less theobromine (found in chocolate and tea), choline and total carbs. Long sleepers tended to drink more alcohol.
It's likely that eating a varied diet is one key to normal, healthy sleep. If you need some help in this area, check out my nutrition plan for a step-by-step guide to optimizing your eating habits.
The Light Connection to Sleep
A discussion about sleep is not complete without a mention of light, or lack thereof. You are biologically programmed to wake and sleep with the rise and fall of the sun. Exposure to artificial light at night, especially blue light, will throw off this programming (aka, your circadian rhythm).
Photoreceptors, or light-sensitive cells, in your eyes track blue light, which in turn triggers different processes in your suprachiasmatic nucleus, a small region in your brain's hypothalamus.
Among them is relaying to your pineal gland the news that when there is a lot of blue light (such as in the case of natural sunlight) the production of melatonin should stop to facilitate wakefulness. As the sun sets and blue light decreases, production of melatonin increases, which helps you fall asleep.
Exposure to LED-backlit computer screens (and other sources of blue light) at night significantly suppress melatonin production and feelings of sleepiness. For many people reading this, blue light exposure at night is likely to be a major factor interfering with sleep.
So, in addition to watching your diet and cutting out sugar-sweetened caffeinated beverages, it's important to take stock of your light exposures for restful sleep.
For nighttime use, swap out your LEDs for clear bulb incandescents, low-voltage incandescent halogen lights that run on DC power or candles. I also strongly recommend using blue-blocking glasses after sundown, even if you use incandescent light bulbs.
Meanwhile, be sure your bedroom is pitch black (install black-out drapes, wear an eye mask and remove other sources of light, like light-emitting alarm clocks), which is most conducive to sleep.
One-Third of US Adults Are Lacking Sleep
In February 2016, the U.S. Centers for Disease Control and Prevention (CDC) reported that 1 in 3 U.S. adults don't get enough sleep.10 In this case, "enough" sleep was defined as seven or more hours per night, but many adults may need closer to eight hours per night (and thus lack of sleep may affect even more than 1 in 3 adults).
The many disruptions provoked by lack of sleep cascade outward throughout your entire body, which is why poor sleep tends to worsen just about any health problem.For example, interrupted or impaired sleep can:
Contribute to a pre-diabetic state, making you feel hungry even if you've already eaten, which can wreak havoc on your weight | Harm your brain by halting new cell production. Sleep deprivation can increase levels of corticosterone (a stress hormone), resulting in fewer new brain cells being created in your hippocampus |
Aggravate or make you more susceptible to stomach ulcers | Raise your blood pressure and increase your risk of heart disease |
Promote or further exacerbate chronic diseases such as Parkinson's, Alzheimer's, multiple sclerosis (MS), gastrointestinal tract disorders, kidney disease and cancer | Contribute to premature aging by interfering with your growth hormone production, normally released by your pituitary gland during deep sleep |
Worsen constipation | Increase your risk of dying from any cause |
Worsen behavioral difficulties in children | Increase your risk of depression. In one trial, 87 percent of depressed patients who resolved their insomnia had major improvements to their depression, with symptoms disappearing after eight weeks |
Alter gene expression. Research has shown that when people cut sleep from 7.5 to 6.5 hours a night, there were increases in the expression of genes associated with inflammation, immune excitability, diabetes, cancer risk and stress11 | Aggravate chronic pain. In one study, poor or insufficient sleep was found to be the strongest predictor for pain in adults over 5012 |
Do You Need Help With Sleep?
A panel of experts reviewed more than 300 studies to determine the ideal amount of sleep and found that, as a general rule, most adults need right around eight hours per night. If you're not getting enough (this refers to the time you spend actually asleep, not just lying in bed), please review my 33 Secrets to a Good Night's Sleep.
You'll find simple tips you can use, starting tonight, to improve your sleep. If, however, you believe an addiction to sugary, caffeinated drinks is part of the problem, be sure to check out Turbo Tapping, which is an extremely effective and simple tool to squelch your soda addiction quickly and painlessly.