If you’ve been diagnosed with obstructive sleep apnea (OSA), you probably know that it’s linked to obesity and weight gain. Losing weight may help with sleep apnea — but can sleeping with a CPAP (continuous positive airway pressure) machine help with weight loss?

The short answer is that by itself, a CPAP machine probably won’t cause you to lose weight. But if you’re already trying to lose weight, it may help support those goals.

What Does CPAP Use Do to Your Body?

Sleep apnea causes your upper airway to close again and again during sleep. When this happens, your body briefly wakes you up so you can start breathing again. Without treatment, this can happen hundreds of times a night. Sleep apnea has also been linked to lower skeletal muscle quality.

A CPAP machine blows air into your mouth and/or nose as you sleep using a mask and tube. This works to improve your sleep by preventing your airway from collapsing and waking you up.

CPAP treatment is the most common and most effective treatment for OSA. Some people who start CPAP treatment notice a major difference in how they feel right away.

Better Sleep

Sleeping better and getting more sleep with a CPAP machine can make you feel more rested, improve your alertness, give you more energy, boost your mood, and leave you feeling less sleepy during the day. Using a CPAP machine can also improve your memory and cognitive skills, such as thinking and solving problems.

Better Health

For most people, treating sleep apnea is important for their overall health. Untreated OSA has been linked to conditions such as heart disease, stroke, and type 2 diabetes. Research suggests that treating sleep apnea may help lower the risk of these and other health problems over time.

By helping you get enough oxygen while you sleep, a CPAP machine may improve many aspects of your health. Consistent CPAP use over the long term can:

• Decrease heart arrhythmias
• Improve blood pressure
• Reduce the risk of heart attack and stroke
• Reduce headaches
• Improve diabetes symptoms

Sleep Apnea and Weight

Poor sleep, obstructive sleep apnea, and weight gain can feed into one another, making each one worse.

In the United States, more than 70 percent of people with OSA also have obesity (a body mass index, or BMI, of 30 or above). Excess body weight can also make sleep apnea symptoms worse. Losing weight can help with OSA symptoms, even if you just lose a little bit.

Improved Sleep and Weight Loss

If using a CPAP machine improves your sleep, it’s probably a good idea to use one. Better sleep can improve your overall health and may also support healthy weight management.

One study of people with OSA found that increasing the number of hours they slept improved metabolism and possibly led to weight loss.

How Obstructive Sleep Apnea Can Cause Weight Gain

There isn’t enough research to say for sure that using a CPAP machine prevents weight gain. However, untreated OSA may contribute to weight gain. Sleep deprivation with OSA can directly harm your metabolism and make you feel hungrier. So if CPAP is an effective sleep apnea treatment for you, it may help you control your weight by reversing these weight-related OSA symptoms.

Sleep Apnea and Hormones

Hormones, chemical messengers in the body, affect how our body burns calories, stores energy as fat, and feels hungry or full after eating. Poor sleep can cause hormonal changes that lead to weight gain.

With OSA, breathing interruptions trigger a fight-or-flight response that wakes you. This stress response floods the body with an excess of hormones. By causing hormone overload, OSA can disturb hunger-related hormones such as leptin and ghrelin, increasing food cravings and feelings of hunger even after eating.

Excess leptin makes it harder to know when you’re full and can lead to accidental overeating. Excess ghrelin levels can lead you to feel hungrier and eat more than you need to.

Poor Sleep and Metabolism Issues

In addition to making you hungrier, the hormones your body releases when you have OSA can also slow metabolism and reduce your energy levels. Disrupted sleep signals your body to store energy rather than burn it, leading to lower resting energy burn and increased fat storage.

When your OSA wakes you up repeatedly, the hormones that flood your system include insulin. The hormones GHS-R and insulin impact how your body stores energy from the food you eat. Having too much GHS-R promotes the storage of fat.

Because insulin controls how your body stores or uses sugar, having too much of it causes insulin resistance, which is linked to weight gain. Insulin resistance is especially linked with increased fat storage in your abdomen (around your belly), and can lead to diabetes.

Speak With Your Doctor

If you haven’t yet been diagnosed with OSA, ask your doctor whether a polysomnography (sleep study) would be right for you. This test can be done in a sleep lab or at home.

Talking to your doctor about your OSA can help you get the treatment you need to feel better and even live longer. With the right treatment options, your doctor can help you get better sleep, feel better, and reach a healthy weight.

Many people find CPAP therapy hard to stick to. Some estimates say that between 20 percent and 50 percent of people who’ve been prescribed a CPAP machine use it poorly or not at all. If you’re struggling to use a CPAP machine, talk to your doctor. There are options that could help you stick to treatment and sleep well.

On MySleepApneaTeam, members often say that while the adjustment period was hard, the CPAP machine ended up working for them. “This is definitely something you will get used to. It will be hard at first, but just try to remember the fact that this is going to help you. That’s how I got through it. Now I don’t even take a short nap without it,” one member said.

Join the Conversation

On MySleepApneaTeam, people share their experiences with sleep apnea, get advice, and find support from others who understand.

How has using a CPAP machine affected your weight? Let others know in the comments below.