Admitting you browse Twitter in bed has become a social shame nearly on par with confessing that you occasionally sneak onto a bar's back patio for a cigarette. We do both with the full knowledge that these habits are bad for us, but sometimes they just feel too damn good to avoid.

But if you're often sleepless or find yourself exhausted during the day, the causes could be deeper than shame-filled 2 a.m. Instagram scrolling. Here are some less commonly discussed reasons you might not be getting in your full night's sleep.

1. Ignoring your circadian rhythms.

Humans are wired to a biological clock that tells us when we need to sleep and when we need to be awake, set to a . That cycle is affected by melatonin, physical activity, social interactions, and most importantly, light.

However, working in offices full of artificial light (and the unpredictability of our days) can set that cycle slightly off-kilter. According to , Ph.D. and vice president of sleep science at , we can start preparing for a good night's sleep at lunchtime.

"An outdoor walk at lunch serves both fitness and sleep; the sun will tell your body it's midday and makes sure the body clock keeps ticking in alignment with the day-night cycle," Raymann says.

2. Working out too close to bedtime.

And if you tend to do more strenuous exercise, hitting the gym later in the day might not be great for your sleep, according to Sujay Kansagra, M.D., director of the pediatric neurology sleep medicine program at Duke University Medical Center and author of the book, .

"For those who have difficulty falling asleep at night, it's important to avoid late night exercise," Kansagra says. "Exercising earlier in the day can certainly help you sleep better at nighttime. However, exercising too close to bedtime can artificially raise your body temperature, which makes it harder to fall asleep."

3. Eating certain foods (especially before bed).

Most of us know that having a venti soy latte with an extra shot right before bed is a terrible idea for a good night's sleep. However, showed that diets low in fiber and high in saturated fat and sugar led to less restorative sleep and more instances of waking up in the night, especially when consumed later in the day.

According to , M.D., professor of neurology at Northwestern University's Feinberg School of Medicine and co-author of the Society for Women's Health Research guide, , our diets can disrupt our circadian rhythm.

"This paper seems to suggest, reasonably so, that the timing of high-carb and high-fat foods has something to do with circadian regulation of body temperature," Attarian says. "Basically, instead of keeping core body temperature low, the metabolism of these high-energy foods at night increases core body temperature, therefore disturbing sleep." Attarian suggests a "light, high-fiber, low-fat meal in the evening" for better sleep.

Keeping blood sugar stable throughout the night is also important for undisturbed sleep, according to , Ph.D., a clinical psychologist and fellow of the American Academy of Sleep Medicine.

"Many people go to bed and by 2 or 3 a.m., their blood sugar is low, so their brain produces cortisol to generate insulin, and that wakes people up," Breus says. "Keeping blood sugar stable at night solves the issue. I ask many of my patients to eat a teaspoon of raw honey 20 minutes before bed. This will help keep blood sugar stable all night long. If honey isn't your thing, try guava leaf tea, but not guava juice or extract. It's got to be the tea."

4. Procrastinating at bedtime.

After a busy day, a quick dinner, and maybe a couple of drinks, it can be tempting to stay on the couch for just one more episode of the new Queer Eye. Sure, you're tired, but the nightly routine just seems like too much, and a quick doze on the couch before the business of getting to bed could seem like just the thing. But that catnap could actually be keeping you up.

"After dinner, start scheduling your sleep and don't procrastinate," says Raymann. "Since it takes some time to fall asleep, and even in healthy sleep you have some short wake periods during the night, you need to schedule around eight hours and 45 minutes of shut-eye time to reach those eight hours of sleep. Avoid napping after dinner time: You might feel like dozing off, but daytime or evening napping can disrupt your nighttime sleepiness and sleep."

5. Worrying with your eyes closed.

The opposite of the quick couch nap at bedtime, getting in bed when you're not tired just to replay every awkward conversation you've ever had can be pretty bad as well, Kansagra says.

"A common cause of difficulty falling asleep is worrying excessively in bed," Kansagra says. "Many insomniacs have become accustomed to worrying when they lay down and have a hard time turning off their minds. One key to improving sleep is avoiding the bed until you actually feel sleepy, and saving the bed only for sleep and intimacy."

6. Binge-watching Black Mirror.

At this point, we know it's a big no-no to bring screens into bed (though, yes, of course we do it anyway). But the TV we watch in the living room could actually be affecting the shut-eye we're getting in the bedroom. Not only does the from the TV mess with our natural rhythms, binge-watchers have , and arousal—the kind you get from a GOT cliffhanger, not the other kind—can affect our ability to get restorative, uninterrupted sleep.

"Try to establish a nightly pre-sleep routine, signaling your body that you're preparing to sleep," Raymann says. "Around an hour before bedtime, dim the lights and engage only in relaxing activities—so no games, no emails, no thrillers on Netflix. Avoid any stress. When it's time to go to bed, also try to stick to a fixed-order routine. Use the bathroom, brush your teeth, and wash and moisturize your face."

7. Tossing and turning.

Waking up in the middle of the night and doing quick math to see how much sleep you can still get if you fall back asleep right this second isn't doing you any favors—anxiety around sleeping actually causes you to , so it might actually be better to get out of bed for a bit to calm down and feel sleepy again.

"When trying to fall asleep again, you might feel disbelief that you'll ever get back to sleep," Raymann says. "Some might feel sleepy again after 30 minutes; for others, it takes longer. The best thing to do when this happens is to get out of bed and try to engage in some relaxing activity under dim light and comfortable conditions. Start reading a book, listen to music, drink some water if you're thirsty."

The most important advice for quality sleep is trying not to panic and remembering to take care of yourself. Be your own best Mary Poppins at bedtime.

"Make sure you're comfortable," Raymann says. "After a while, the sleepiness will kick in—and then it's time to go to bed again."

Emily Alford lives in Brooklyn, NY, and writes about beauty, food, and TV. Sometimes all at once. Follow her on Twitter

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