What Your Doctor Should Monitor During an Extended Fast

Extended Fasting is generally safe for most people. There are a few exceptions - please check out our guide to Safe Fasting if you would like to know more about them.

But it’s a good idea to have your doctor monitor you, especially if you already have health conditions or you’re on medications.

Let’s look at what your doctor should be checking for. 

What is an Extended Fast?

Technically, an Extended Fast would be anything more than 3 days or so. 

But for the purposes of this article, a 3 day fast probably won’t require you to check in with your doctor. 

Unless you have ongoing medical conditions, then it’s important to keep your doctor in the loop. 

But let’s say you’ve decided to do a 30 day fast. 

Maybe you’ve got some health issues you want to reverse. Or you are obese and really need to put a dent in your weight. 

Whatever your reason, you’re going to want to keep tabs on some things. 

First step

First step is to speak to your doctor and let them know you’ve decided to do an extended fast. 

Tell them you want to get some baseline numbers before you start. 

Most doctors will know what needs to be monitored. 

But some doctors unfortunately have no clue when it comes to fasting. 

If that’s the case, here’s some things you should request baseline numbers on at the beginning of your extended fast:

CMP

A CMP is a Comprehensive Metabolic Panel. 

It’s an extended version of the Basic Metabolic Panel (BMP) and what we’re looking for here is your electrolyte balance.

It’s a good idea to know how your electrolytes are before you start the fast. 

Many people are already deficient in sodium, magnesium, and/or potassium when they come into fasting. 

And when you start losing fat, you lose a lot of water, and with it electrolytes. 

You will need to supplement electrolytes during your extended fast, but if you find that you’re already low, you can bump them up before you start. 

A CMP can also look at your blood glucose levels at the start, another good thing to know. 

Your doctor might also order a fasting blood glucose test. 

CBC

A CBC is a Complete Blood Count. 

It is a blood test that measures the number and type of blood cells. 

The reason you want to look at this when it comes to extended fasting is that it can tell you if you are anemic. 

You need to know that before you head into an extended fast. 

Overall Health

If you haven’t had a general physical in a while, this is a good time to have it. 

Your doctor will check your weight, height, and things like heart rate and blood pressure. 

What’s next?

Depending on how long you are going to fast, your doctor will then need to monitor you.

They might want to do something like a BMP (Basic Metabolic Panel) every week or every two weeks. 

The BMP is not as comprehensive as the CMP, but it’s perfect for monitoring you during the fast. 

They might also check your glucose and your vital signs, as well. 

You can discuss with your doctor how often they want to check things. 

And of course always reach out to your doctor if you’re having issues during the fast. 

What if my doctor says no?

Some doctors are not comfortable with Extended Fasting. 

We will have an article coming soon with more tips for what to do when your doctor says no.

But for now, ask your doctor why they are saying no.

Is it because of an ongoing health issue?

Or do they just not understand fasting, or have little experience of monitoring it? 

Once you understand why your doctor is saying no, then you will have to make a decision about whether or not you wish to do an Extended Fast. 

We, of course, cannot give you medical advice and we cannot tell you not to listen to your doctor. 

And as always, if you have medical conditions or you are on any medications, it is super important that you stay in touch with your doctor. 

Be smart!

As we said before, Extended Fasting is usually safe for most people. 

But there’s no reason not to go into it prepared. And knowing your baseline numbers is a good way to start.