If you're having trouble losing weight, it may not be your kitchen you need to think about — it might be your bedroom. We asked neurologist Sujay Kansagra [1], MD, to explain how sleep affects weight [2] and what you can do under the covers to help shed pounds. According to Dr. Kansagra, Mattress Firm's sleep health expert, there are four connections between lack of sleep and weight gain.

How Sleep Affects Food Intake

Those that sleep less generally eat more, which is why lack of sleep can lead to weight gain. Dr. Kansagra said this may seem like common sense since the more time you spend awake, the more time you have to consume calories, but it's not just a matter of time. "Our brain chemistry changes with sleep deprivation. Studies have shown that sleep-deprived individuals eat an extra 385 calories per day [3] on average," Dr Kansagra explained. "Yet the calories they spend are not significantly different from those that sleep more." These extra calories add up quickly over time, making it clear why sleep deprivation can cause weight gain.

How Sleep Affects Impulse Control

Not only does sleepiness make you eat more calories, but it also makes you more likely to eat the wrong things. Dr. Kansagra said, "Sleep deprivation affects the brain's ability to control impulses and make smart decisions." Dr. Kansagra added, "Separate studies show that sleep deprivation increases your chances of eating high-fat and carbohydrate-rich foods [4]." So you're not the only one craving doughnuts and pizza when you didn't get enough sleep the night before.

How Sleep Affects Metabolism

If that weren't enough, our body's' metabolism [5] also pays the price for skimping on the shuteye. "Cortisol, known as the stress hormone, increases with sleep deprivation [6], and this signals your body to store away calories as fat." Dr. Kansagra went on to explain, "Insulin, which is in charge of pulling sugar out of your blood stream and into your cells, doesn't work as well, leading to higher blood sugar levels, and once again, more calories converted to fat." Increased cortisol and insulin from lack of sleep cause weight gain, which "all compound to create a viciously unhealthy cycle."

How Sleep Affects Exercise

Not getting enough zzz's makes you consume more calories and increases cravings for not-so-healthy foods, but Dr. Kansagra said that sleep deprivation also leads to fatigue, preventing you from having the energy or the desire to expend those calories through exercise. If you go to bed late, that early morning workout is much less likely to happen.

These are the four reasons why sleep deprivation is the perfect storm to destroy your resolution to lose weight. So Dr. Kansagra said if there's one thing you can do to lose weight, it's to "focus on getting an appropriate quantity and good quality of sleep. Adults require seven to nine hours [7] to feel fully refreshed." Are you getting enough?