There’s a well-known correlation between sleep apnea and being overweight. In fact, treatable levels of sleep apnea are found in about 40% of people with obesity. And, if you look at the data from the other direction, you’ll find that approximately 70% of people with obstructive sleep apnea are obese.

But does sleep apnea cause weight gain (or vice versa), or are the two factors actually unrelated to each other? Read on to find out more.

What Is Sleep Apnea?

Sleep apnea is a condition where the airway is partially blocked and in some instances, breathing stops for spans of more than ten seconds throughout the night. Symptoms include feeling exhausted during the day, waking up during the night, snoring and gasping for air while sleeping.

There are two main types of sleep apnea. Central sleep apnea, the less common type, results from faulty signals coming from the brain. This may be due to complications from an illness, opioid use, or other neurological factors. Basically, the brain “forgets” to tell the body to breathe during sleep.

The more common type is known as obstructive sleep apnea (OSA). During sleep, your neck muscles naturally relax. If you have OSA, this can cause the tissues of the airway to collapse or fold in on each other, blocking the passage of air.

In some cases, people experience both the obstructive and central types of sleep apnea at the same time. This is known as mixed or complex sleep apnea. Doctors are still trying to understand the cause of this disorder as it presents differently in every patient.

These periods of hypopnea (dropping oxygen levels) and apnea (no breathing) will repeat throughout the night. Along with fatigue and snoring, sleep apnea can also contribute to the development of other health conditions. These include diabetes, high blood pressure, and heart disease.

How Does Gaining Weight Affect Sleep Apnea?

Not everyone who is overweight or obese will develop sleep apnea. However, being overweight and/or gaining weight does increase your risk of developing the disorder.

When the muscles in your neck relax during sleep, they no longer support the weight of the tissue on top of them. The more weight pressing down on the airway, the more likely it is to collapse. Because of this, people who carry a lot of weight around their neck and chest are at a much higher risk of OSA.

If you gain even 10% of your weight (for example, a 150 lb person gaining 15 lbs) your risk for developing sleep apnea gets multiplied by six.

Does Sleep Apnea Cause Weight Gain?

It’s pretty clear that weight gain can contribute to sleep apnea, but does it also work in reverse?

Unfortunately for many people, the answer is a resounding yes. A lack of oxygen during sleep can impact your ability to maintain a healthy weight in more ways than one. 

Low Energy and Chronic Fatigue

Even one night of poor sleep can leave people feeling like zombies shuffling through the day. So imagine the impact that months—or even years—of restless sleep can have on energy levels.

Similar to a phone’s Battery-Saver Mode, when experiencing lower energy levels, we conserve the little energy we have by performing only essential tasks (like eating and going to work) and avoiding the non-essential ones (like going grocery shopping or to the gym). This can lead to eating unhealthy foods out of convenience and sitting still for longer periods of time.

Slow Metabolism

Your metabolism refers to the rate at which your body burns the calories you consume. When you’re fatigued, your lifestyle becomes less active and you’ll expend fewer daily calories. Over a period of time, this lifestyle change can lead to an actual drop in your metabolism, making you more likely to gain weight even without increasing your caloric intake.

Hormonal Changes

If you’re not getting restful sleep because your airway is blocked and you have disordered breathing with obstructive sleep apnea, your body is fighting against you. The hormonal imbalance that results from poor sleep makes weight loss nearly impossible.

The lack of quality sleep will put your body under enough stress to disrupt your hormone production. Leptin, the hormone responsible for sending “your-stomach-is-full” signals to your brain after eating, decreases when you’re sleep deprived. And to make matters worse, ghrelin—the hormone responsible for sending “I’m-hungry” signals—increases.

So when you don’t get enough good sleep, your hormones tell you to eat more and won’t signal you to stop. 

Increased Cravings and Decreased Willpower

Lack of energy, slow metabolism, and hormone changes can create a perfect storm of weight-gain factors. Another one of those factors is that when we’re feeling tired, we’re much more likely to crave foods that give us a quick energy boost like those high in sugar and simple carbs. 

Being exhausted also decreases our willpower, making it much harder to put effort into making healthy choices.

Will Losing Weight Reduce OSA Symptoms?

Without getting proper treatment for both your OSA and taking steps to maintain a healthy weight, a vicious cycle occurs. Weight gain can lead to sleep apnea, which can lead to weight gain, which makes sleep apnea worse, which leads to more weight gain and so on. And if you’re balancing other health conditions at the same time, the cycle becomes harder to break.

On the positive side, this cycle can work both ways. Getting treatment for your OSA can improve your sleep quality, making it much easier to lose weight. And research has shown that losing even 10% of your weight can lead to a 20% drop in the severity of OSA symptoms.

Getting Help for Your Sleep Apnea

So does sleep apnea cause weight gain? It can, but the relationship between body weight and OSA is too complicated to explain with a simple yes or no answer. Maintaining a healthy weight or losing weight, however, can improve your symptoms.

If you suspect you’re suffering from sleep apnea but haven’t yet been evaluated or sought diagnosis, Sleep Centers of Middle Tennessee can help. Contact us today to find out what to expect as a new patient.