Did you know that the key to losing weight without eating less could be extra time between the sheets? No, we’re not talking about burning calories during sex, although that won’t hurt, chances are, you need to get more quality sleep. The average American is getting less than the recommended seven to nine hours a night, and it’s hurting their health.

Luckily, the scientific community and researchers are applying more time and effort to studying sleep and its overall impact on our health — although much is still unknown about what’s going on while we snooze.

Many studies are finding associations between not getting enough quality sleep and metabolic health challenges, from larger waistlines to deep belly fat, higher risk of type 2 diabetes, and messed-up hunger hormones that make you more likely to consume additional calories the day after poor sleep.

Here’s how sleep — or lack thereof — could be impacting your waistline and weight.

You’re staring at a screen before bed.

You’ve probably heard before that you should avoid electronics that emit blue light from their screens and power down at least an hour before bedtime. The reason is that your eyes’ exposure to blue light messes with your body’s production of melatonin, the hormone that helps you sleep. Spending time on your smartphone or laptop before trying to fall asleep can impact (read: confuse) your body’s circadian rhythm, its natural clock. Not only does blue light exposure make it harder for you to fall asleep, but a small study discovered that this environmental light might impact glucose metabolism levels in normal-weight adults.

You drank too much before turning in.

You may have experienced this conundrum after having a few too many cocktails or glasses of wine, but the medical community has proven that alcohol consumption can interfere with sleep quality. Sure, you probably feel sleepy after a few drinks, but the alcohol actually blocks REM sleep, meaning that your sleep quality overall is poorer.

You’re on a diet and so hungry you can’t sleep.

If you’ve kick-started a new weight loss plan, not eating enough could be contributing to your sleep issues. That’s probably because your rumbling stomach and hunger pains are interfering with your ability to relax and fall asleep, according to the Alaska Sleep Clinic. Make sure that even on a diet you are eating the correct amount of nutrients in a day to avoid this problem entirely.

You stayed inside all day and watched TV on the couch.

Not only were you lazy by lying on the couch all day, but lack of sunlight can disrupt your sleep cycle, making it more difficult to fall asleep when you want and sleep soundly throughout the night. This is why it’s wise to get exercise during the day, and preferably outside. One study found that exposure to natural light during the day improved workers' sleep that night, which was linked to improved productivity and quality of life.

You didn’t handle that stressful situation.

Ever have that day where you’re going like the Energizer bunny and don’t stop and relax until your head hits the pillow at night? What happens after that? You can’t fall asleep. That’s because you feel stressed and didn’t take a break or let your mind have some downtime — so those racing thoughts keep racing. Stress can keep you awake at night, which can then make you feel sleepy and more overwhelmed the next day because you’re tired. When you feel stress, your body releases the hormone, cortisol, to help you get out of that situation (igniting ‘flight or fight’ mode). If you’re never dealing with that stress in a healthy way, higher levels of cortisol may be in your body and you may have a harder time getting rid of belly fat, according to research. Address stress in a healthy way by trying relaxation techniques or meditation before bed. Even writing out a future to-do list for 5 minutes before bed may help you fall asleep faster.

You’re not putting yourself to bed on time.

Chances are, you or your partner are amongst the 1 in 3 Americans that don’t get seven or more hours sleep, according to the CDC. That’s probably one of the reasons you struggle to lose weight or to keep extra pounds at bay. Increased stress, hunger hormones out of whack, and abnormal timing of light exposure may be causing you not to sleep well, which can make trying to lose weight even more of an uphill battle. So do yourself and your waistline a favor and get to sleep on time.