Is it Safe to Fast After WLS?

We hear a lot about fasting these days, but is it really safe, especially after weight loss surgery? There are differing opinions out there on this topic when it comes to bariatric surgery. A lot of people will tell you that you just naturally intermittent fast after weight loss surgery because your eating schedule changes and you will probably only eat during certain times of the day. Some people swear by this and believe it has really helped them stay on track after bariatric surgery. On the other hand, there are others out there that believe you should not restrict to this degree after bariatric surgery since we are already at risk for becoming deficient after the procedure. So, let’s explore both sides to this debate.

Intermittent fasting is something a lot of people are trying these days and I can speak from experience as I followed the 16/8 method for a little while after my surgery. This pretty much means that I would only eat during an 8-hour period, and then I followed a fast for the other 16 hours of the day. To be honest, I started it on accident because I was skipping breakfast and then just ate dinner really early in the night. I noticed that I was having success with my weight loss so I decided to just truly call it fasting and make sure I was staying between that timeframe when I ate. This method of fasting you might see in the bariatric community because there is still enough time in the day to allow you to get enough protein and nutrition. To be honest, I think it teaches you not to eat past a certain time at night, which was always a problem for me at my heaviest. Some people work really well when they have a schedule to stick to and intermittent fasting with a schedule such as the 16/8 method can really help some patients.

There are other versions of fasting out there where you go 24-hours at a time without eating and I definitely would not recommend this for bariatric patients. We are already struggling with deficiencies after surgery and it is not safe to neglect your body of nutrition for that long. The problem we have with fasting for too long is that we can get hypoglycemia if we go too long without eating. This is very uncomfortable and something that you definitely do not want to experience after surgery. It is important that you nourish your body and you do not let your blood sugar get too low. Another huge issue that can occur is dehydration. Again, as bariatric patients, we are already extremely sensitive to this. It is important not to add another complicated layer to the mix. 

This topic can be extremely confusing because there is so much research on both sides of the fence. No matter what side you are on, it is important to discuss this with your surgeon before ever attempting to start a fast. Plenty of research out there highlights the benefits of fasting, but this does not always mean it is the best choice for bariatric patients due to our new anatomy and the way we have to change our lifestyle to ensure we do not get deficient. I think it is important to really evaluate whether or not you believe you can get enough nutrition in for the day following a 16/8 method and then discuss with your surgeon and nutritionist how you plan to do that. Just remember that it is already extremely difficult to find enough hours in the day to hit your protein and water goals, so if you remove even more hours from the day, you risk not getting it all in. Always remember to put your health first and never choose to fast for unhealthy reasons as you do not want to starve yourself and end up on the other side of the spectrum after bariatric surgery. Be smart about your diet changes and always do your research before trying something new. Remember, you are not on this journey alone, so utilize your team of support to make sure you are making the best decision for your health.