Why adopting an “I’ll sleep when I’m dead” mentality is negatively affecting your weight (and a bunch of other things).
We’ve all heard about the importance of diet and exercise on health and performance, but did you realize sleep is just as important? With schedules that are packed with work, school, social and family obligations, (the list goes on), sleep often feels like an afterthought. You know, that thing you get to when everything else on the checklist gets done? But having good sleep habits allows our bodies to recover, promotes hormonal balance, results in improved focus and increased ability to handle stress (both mental and physical). Poor sleep habits, on the other hand, can result in fatigue, reduced performance, higher body fat percentage (2), hormonal imbalance (12,13) and increased risk for illness and injury (1). According to the CDC, over 1/3 of American adults sleep less than 6 hours a night on average (the recommended minimum is 7 hours per night to keep potential health problems in check.) Recently, a major review found that shortened sleep (less than 6 hours per night) resulted in an increased likelihood of obesity in both children (89%) and adults (55%). Another study found that when restricted to 5 hours of sleep for 5 nights, participants gained an average of 1.8 pounds (4). Now imagine if that happens more than just five nights out of the year.
How can it have such an impact?
The majority of current research looks at what happens when sleep is purposely restricted and then watches for what happens (versus looking at the benefits of getting enough sleep). There have been a variety of studies performed looking at both biological and behavioral outcomes of sleep deprivation or “loss of sleep”. Below is a brief overview by topic:
Hormones: We know that missing out on sleep can negatively affect hormone regulation including some pretty key players in terms of metabolism and hunger signaling.
- Insulin – Sleep deprivation reduces insulin sensitivity and, therefore, glucose tolerance. This can happen when you get half your normal sleep for less than a week or a loss of 90 total minutes over a few weeks (example: crunching for exams or working to meet a big deadline) Luckily, this trend seems to normalize quickly once you’ve caught up on rest.
- Androgens – Specifically testosterone (think muscle building). Studies have shown that getting three fewer hours of sleep for five days reduced testosterone levels by 10-30%! However, this too is quickly reversed with adequate rest.
- Growth hormone (GH) – Growth hormone stimulates muscle growth, repairs cells, builds bones and helps with recovery. Getting less sleep or having irregular sleep (aka shift work) changes the GH cycle. Good news is that these disturbances don’t seem to reduce overall exposure to GH throughout the day.
- Cortisol – Often referred to as the “stress” hormone, cortisol mediates the process of waking up. It typically highest in the morning and decreases throughout the day. Chronically elevated levels of this hormone can be catabolic (causing break down) in muscle tissue and can cause inflammation. One study found that getting only four hours of sleep resulted in a 50% increase in cortisol over a 24-hour period (12-13).
- Studies have noted an increase in overall food intake following a few hours of sleep deprivation over four days. One study found that just 1 hour less than usual resulted in participants eating 45% more food. Sleep deprivation results in changes in two hormones that regulate appetite. Specifically, a reduced production of leptin (tells you you’re full) and increased ghrelin (tells you when it’s time to eat). Behavioral data reveal that metabolically healthy, sleep-deprived subjects prefer larger food portions, seek more calories, exhibit signs of increased food-related impulsivity, experience more pleasure from food, and expend less energy.
- Overall, it doesn’t look like a reduction in sleep directly suppresses the metabolic rate, but it may do so indirectly via reduced physical activity. Researchers note that sleep-deprived participants have reduced NEAT (non-exercise activity thermogenesis), or the energy your burn from fidgeting/movement throughout the day, compared to their well-rested counterparts (never mind getting to the gym). And regardless of metabolic rate, sleep deprivation combined with caloric restriction (often seen in those people trying to lose weight) results in less fat mass lost than if one were fully rested.
- Acute sleep loss or disrupted sleep has also been shown to alter the balance of gut bacteria away from more beneficial bacteria resulting in increased fat formation and inflammation (14). Recently, the gut has been widely implicated as a key for maintaining balance in the body through regulation of metabolism and immune response.
(Although the current research has shed light on how short periods of sleep loss can affect energy metabolism, longer-term studies are needed to validate these findings.)
Okay, so sleep is important, but how much do I need?
The standard recommendation for most adults (18+) is 7-9 hours of sleep per night. Adolescents and teens can often need up 10 hours. But sleep needs are highly variable between individuals and it might take some experimenting to find the perfect amount for you (see the activity below). It’s also important to note that there are certain situations in which more sleep is necessary – such the case with athletes as during times of increased stress.
|National Sleep Foundation recommendations based on age-group:|
|School-aged children||9-11 hours|
|Older adults||7-8 hours|
Determine your sleep needs:
Start at 7 hours and experiment over the next few weeks to find your ideal amount of sleep. For example, if you need to be up at 6 AM, you’ll want to be asleep by 11 PM. This means starting your bedtime routine around 10:30 PM. If you fall asleep within 20 minutes of your head hitting the pillow, and you wake up without an alarm, you are probably getting the right amount of sleep. In contrast, if you’re falling asleep as soon as your head hits the pillow and you need an alarm to wake up, you might need more sleep. If this describes you, or you’re consistently getting fewer then 7 hours of sleep per night, it’s okay! Work your way up slowly by getting to bed 30 minutes earlier each week until you fully rested upon waking (listen to your body cues).
5 signs your sleep habits aren’t working for you:
- Your mind feels foggy – what we learn, and experience gets transferred to long-term memory while we sleep. Without this you could experience: reduces alertness or concentration, confusion, impaired judgment, and forgetfulness.
- You’re getting sick more often – without enough sleep, research shows a decrease in the number of immune cells and an increase in inflammatory markets. This results in increased vulnerability to pathogenic viruses and bacteria, increased risk of acute illness, increased risk of heart disease and other inflammation-related illnesses.
- You’re feeling down in the dumps – While we sleep, our bodies work to balance out important neurotransmitters and regulate hormone production. Without this you could have: impaired regulation of emotions, heightened stress, low mood, and the increased risk of depression.
- Your workouts feel harder than they should – just like with mood regulation, our body works to balance neurotransmitters and metabolites important for physical performance. The following could be signs of poor recovery: slower reaction time, low energy or endurance, reduced desire to exercise/depressed mood.
- You’re struggling with weight loss – poor sleep has been linked to excess body fat and can disrupt appetite regulation causing you to feel hunger and take in excess calories.
This all sounds like me, how do I start getting more sleep?
Sleep should be a priority, but often times work or an extra episode on Netflix often wins out. In addition to using the nutrition tips and sleep hygiene tools listed below, I recommend taking a critical look at where your time is being spent, especially at the end of the day.
Sleep Hygiene basics:
- Create a nighttime ritual. To go from waking to sleep, your body needs cues to tell it to wind down and transition to restfulness. Keeping a consistent schedule that allows you to wake up and go to bed around the same time can help with this. When you’re consistent, your body will begin to release calming hormones before bed and stimulating ones before waking – your body is its own clock if you train it to be.
- Limit caffeine and alcohol. The quantity of sleep you get is important, but so is the quality. Caffeine and alcohol can interfere with deep restorative sleep, limiting recovery benefits and causing you to feel less rested. Skip the coffee and other caffeinated beverages after 1 PM.
- Time and size your meals appropriately. Too much food can make it difficult to fall asleep. Instead, try eating a moderately sized meal a few hours beforehand (at least 2). In the same thought, try not to drink excessive fluids before bed to limit the need to get up throughout the night.
- Do a data dump. Use stress-reducing techniques such as meditation, gentle stretching/yoga, or writing in a journal to calm the mind, release tension, and activate calm-down signals in the body.
- Ditch the screens. Remove all devices at least 30 minutes before bed. Artificial light interferes with the production of melatonin, the hormone that helps regulate sleep and metabolism. Turning down the brightness on your devices or investing in blue-light blocking glasses can help here.
- Create a good sleep environment. Your bedroom should be quiet and free of anxiety-free. Maximize melatonin production by making the room as dark as possible. Research also shows that cooler temperature help improves sleep quality (around 67*F).
- Exercise regularly, but not too close to bedtime. Experts recommend you leave about 3 hours between the gym and bed (save the heart pumping activities for the morning.)
4 foods that promote sleep:
- Tart cherry juice. Made from sour cherries, tart cherry juice is one the best natural food sources of sleep-promoting melatonin. A small 4oz serving should do. Also eat pistachios, eggs, fish, black rice, red rice, sprouted lentils.
- Yogurt is an excellent source of tryptophan, an amino acid that’s needed to synthesize the sleep-regulating brain chemical serotonin. Serotonin is also thought to increase the secretion of the sleep hormone melatonin. Also eat milk, turkey, hemp seeds, eggs, Parmesan cheese, edamame, tofu, kidney beans, lima beans, tuna, pumpkin seeds
- Eating fish at least once a week has been shown to improve sleep in children and adults. This is because the omega-3 fatty acids in oily fish (specifically DHA or docosahexaenoic acid), has been shown to help regulate the production of inflammatory mediators and melatonin. Fish is also high in Vitamin D and vitamin B6, a nutrient needed to convert tryptophan to melatonin. Also eat sardines, anchovies, Arctic char, trout, tuna, herring, and mackerel.
- Kiwi is a good source of serotonin, which helps initiate and maintain sleep. It’s also thought that antioxidants in kiwi, such as vitamins C and E, play a role in the fruit’s sleep-promoting properties. Also eat Pineapple, banana, plums, tomatoes, plantain, spinach, walnuts.
Supplements and Herbs
If you’ve tried all of the lifestyle and diet tricks listed above and are still having trouble getting adequate restful sleep, you may also consider some of these over the counter dietary supplements. However, you should always consult a health care professional before to ensure it is safe.
- Melatonin – Often called the “sleep hormone”. It can reduce the time it takes to fall asleep but is unlikely to do anything if you do not have problems falling asleep. I don’t recommend relying on this as a long-term solution as it does not solve the underlying problem preventing sleep in the first place. Remember, melatonin production is suppressed by exposure to light, so try diming the lights an hour before bed instead.
- Magnesium – is nature’s original chill pill. You want to look for it in “magnesium glycinate” form for optimal relaxation effects. In addition to a mineral supplement, foods like goat’s milk kefir, spinach, pumpkin seeds, and dark chocolate are all good sources.
- Valerian Root – This herbal remedy has been used for centuries (think ancient Greece) to ease things like insomnia and nervousness. It is available as a capsule or in tea but there is no standard dose and it can affect everyone differently. Valerian can make you drowsy, so you should only take it near bedtime.
- 5-HTP (5-Hydroxytryptophan) – Helps the body create serotonin (a neurotransmitter that helps regulate sleep-wake cycles and a precursor to melatonin). Research shows it can help you fall asleep faster and stay asleep longer. 5-HTP can interact with some medications; you should not take 5-HTP if you take an MAOI.
- Lavender – as aromatherapy is very calming. Use a mist diffuser or simply put a few drops of essential oil near your bed while you sleep for continuous relaxing effects.
Everything from decision making to proper digestion is dependent on quality sleep and sleep duration is predictive of weight loss when following a diet and exercise program. The good news is that just one sleepless night is not the end of the world. Our bodies are very resilient and bounce back quickly with adequate rest. So, don’t worry if you toss and turn once in a while. However, consistently getting less than ideal sleep can have negative consequences on both health and performance. As sleep becomes more of a priority, you might notice some pretty rad side effect like faster reaction times, improved energy and even weight loss. I tell my clients to think of sleep as the “save” button on Word document, you don’t want to lose all that hard work you did the day before!
Here are a few snacks for getting a good night’s sleep:
- Half a banana with a few almonds
- 5 Crackers with 1 tsp almond butter
- ¼ cup oatmeal with dark cherries
- Small Ezekiel bread wrap with 1oz turkey and 1 tbsp cranberries
- 4oz kefir with turmeric and cinnamon
- Chamomile or passionflower tea
Written by Laine Greenawalt MS RDN LDN
Follow Laine on Twitter @LGreen_11
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