19 April 2019

Stop CPAP causing Weight Gain: Use Bilevel

“When you get into a tight place and everything goes against you, till it seems as though you could not hang on a minute longer, never give up then, for that is just the place and time that the tide will turn.”    
- Harriet Beecher Stowe (American Author – 1811 – 1896) 

Many people including myself when using CPAP have had Weight Gain. A number of people have detailed their experience on the various sleep apnea forums (listed right hand side). In addition, some sleep medical specialists are unsure of how to stop CPAP causing weight gain and why more patients do not have weight loss. Should CPAP be causing weight gain, seriously consider using a Bilevel or BiPAP Auto adjusting pressure machine. From my personal experience, when you use a bilevel machine, you will be able to get rid of any weight gain and achieve weight loss!

You can read articles on CPAP and weight at:    

As mentioned on the blog page Why is CPAP Compliance Rate Low? it is likely that up to an estimated 80% or more than 15 million users of the sleep apnea machines are non-successful, non-compliant and failing. I have detailed on various posts and pages what I did to finally overcome all the side effects and issues that I was having using the sleep apnea machines especially CPAP therapy. 

The question is: Should you be experiencing weight gain after starting CPAP therapy; what, if anything can be done about your sleep apnea therapy? 

After starting CPAP therapy, I gained weight of up to 2 kgs. The sleep medical specialists may consider that it is not much of a weight gain. However, I did not lose weight as I was lead to believe when I began using a CPAP machine. The weight gain happened despite exercising up to 5 times per week for greater than 30 minutes at a time including walking up and down hills. Also my diet was being watched every day and my body mass index (BMI) was 26. In addition, I was having yearly medical checkups including blood tests. I thought I was doing everything possible to lose the weight that I had put on even outlaying money to buy a CPAP auto adjusting machine. 

Though I did all these things, I still could not lose the weight that I had put on since starting CPAP therapy. This is the reason for the quote at the top of the post by Harriet Beecher Stowe. Just when you think you have run out of options, hang in there a bit longer, you have some luck and the tide turns! 

In 2014, after being unsuccessful for nearly 4 years with trying to resolve the various side effects and issues caused by using the CPAP fixed pressure and auto adjusting machines, I decided to purchase a ResMed VPAP S9 Bilevel Auto adjusting pressure machine. Now known as ResMed AirCurve 10 VAuto. More details at The Secrets to Success using CPAP and Bilevel.

It was after using the Bilevel machine and optimizing the settings on the machine that I was able to take off all the weight gain that I had put on after starting CPAP therapy. Further, my weight has now dropped more than 1 kg below my pre CPAP weight of nearly 9 years ago and I currently have a BMI of 25! 

Buying the Bilevel machine was a huge leap of faith and I did have some luck in buying the machine. I thought the machine would work great; however, at the time I had little knowledge of how the machine truly worked with all its various options. There was no way of knowing this until I actually used the machine each day. After some time using this particular machine, I was able to resolve all the issues that I was having with my sleep apnea therapy. Have a look at the improvement in a comparison of CPAP Vs Bilevel Settings Example.

On the blog post Use Different CPAP and Bilevel Pressure Settings and the blog page Different Bilevel Settings Example, I advised that using the one setting on your sleep apnea machine was not always appropriate in all situations. For example, when eating and drinking late at night, I use a Bilevel Auto machine with Pressure Support of 5.0 cmH2O. Using Pressure Support greater than 3.0 cmH2O stops me from hyperventilating or over-breathing when asleep and waking up feeling tired in the morning. Importantly, median Minute Ventilation rate at 6 litres/ minute or lower can be maintained.  
Based on my personal experience, using Pressure Support greater than 3.0 cmH2O has good implications for those users who have gained weight since starting CPAP therapy and/ or have a high BMI. A discussion with a medical specialist at one of the major equipment suppliers supports this conclusion. 

Unfortunately, a major weakness of both the CPAP fixed pressure and auto adjusting machines is that maximum pressure support is limited to only 3 cmH2O. 

As further discussed on the blog page Guide to Success using CPAP and Bilevel, the steps to take to optimize your sleep apnea machine settings are:  

1. Have a regular Apnea-Hypopnea Index (AHI) of 1.5 or lower. Does not have to be daily, but ideally most of the time;  

2. Minimize Leaks from the Mask and Mouth Breathing. Ideally reduce Leaks to Nil so that a Zero appears on your sleep machine every morning; 

3. Reduce median/ average pressure of IPAP (inhale pressure) and EPAP (exhale pressure) as much as possible. The maximum or top pressure is only required as necessary to cover obstructive sleep apneas. 
4. Reduce median/ average Minute Ventilation (MV) to 6 litres/ minute or lower and keep the 95% to 100% rate “under control”. Apply the principles of the Buteyko Breathing Method to your sleep apnea machine by slowing your respiratory rate down and reducing the volume of air that you are breathing in. 

For tidal volume settings, I use Ideal Body Weight (IBW) on CPAP and Bilevel or Predicted Body Weight (PBW) not my actual body weight. Normal MV rate is considered to be 6 litres/ minute per Medical Textbooks. Further information on Minute Ventilation and the Buteyko Breathing Method is at: https://www.normalbreathing.com/.
By optimizing the settings on a Bilevel Auto adjusting pressure machine, the tide turned and I was able to stop CPAP causing weight gain. In addition, I was able to get rid of any weight gain and achieve weight loss of more than 1 kg from my sleep apnea therapy! A comparison of the two machines is at CPAP Vs Bilevel Settings Example. 

Dr Steven Park, Medical Surgeon wrote on a blog post 7 October 2020:

It turns out that overall, CPAP use has been found to increase weight significantly, in proportion to how long you use CPAP. The more hours you use CPAP every night and the more number of years, the higher the amount of cumulative weight gain.

Go onto the Comments section and see many people who have put on more than 10 pounds or 5 kgs since starting CPAP! 


An additional reason to seriously consider using BiPAP and Bilevel auto adjusting machines rather than CPAP is that they may improve any back and neck issues that you may have. From personal experience, on changing to a bilevel machine, my back and neck issues improved by 5% to 10%!

Since originally writing this blog post, in early 2021 I began using a very high starting IPAP of 18.2 cmH2O and EPAP of 13.0 cmH2O (inhale and exhale pressure). Ideal Body Weight was used in setting the median Tidal Volume and Minute Ventilation. This was essential to stop hypoxia (oxygen desaturation) and sleep disordered breathing causing the symptoms of Dementia. More details are on the blog post:
Should you be having side effects and issues with your sleep apnea therapy; CHANGE what you are doing so that you can wake up feeling refreshed and energized each day. 

“Have courage. Be adventurous and Go for it! Overcome your fear.”
- Mrhelpful


  1. Hello and thank you for your work here!

    I have switched from a BiPap to an ASV (Res Med AirCurve 10 ASV), and I'm much more comfortable. But I had weight gain on both and cannot lose it.

    What is the mechanism of the weight gain? Is it hormonal?

    Thank you.

    1. The secret was to slow my breathing rate down and reduce the volume of air that I was breathing in. To apply the principles of the Buteyko Breathing Method to the sleep apnea machine. Suggest you download the Oscar/ Sleepyhead software (listed right hand side) and review your Minute Ventilation rate.