When and How Should you Measure Ketosis?

 In Nutrition

If you are following a low carbohydrate diet that is based on the ketogenic principles then measuring if you are in ketosis may be an important goal for you. There are times when measuring the specific ketone level may not be required.

When is measuring ketosis really needed?

My advice to people is if you are following a ketogenic diet for a therapeutic reason (such as epilepsy, cancer, MS, diabetes etc.) then measuring the ketogenic level will be important for you. This is because from the evidence that we have to date, we can see some correlation that in order for the ketogenic diet to be effective, the ketone bodies need to be consistently elevated.

If you are someone that is following a ketogenic diet for weight loss, then measuring ketosis through objective ways (I will go over them below), really may not be necessary. There is still this notion that I see online form various Keto Coaches that having a high ketone level in the blood or breath will automatically mean you will lose more weight. I want to say categorically that this is NOT the case.

“High blood ketone levels do not automatically mean you will experience a fat loss”.

In the next few weeks I will detail in a weekly email exactly why this is the case but for now back to the topic of how to measure ketosis.

How to measure ketosis?

Subjective Measurements:

There are several ways in which you can detect if you are in a ketogenic range. The first way is looking at more subjective measurements. What I mean by this is measurements that focuses more on how you are feeling. In the beginning, you can experience certain symptoms including:

  • nausea,
  • headaches,
  • fatigue,
  • bad breath and weak legs.

These symptoms are a sign that your body is now switching from using glucose to using fat for energy.

Another subjective measurement to look at is that of hunger. When you have fully allowed your body to become keto-adapted, it often correlates with a decrease in hunger. If you are or do still feel hungry, then it is more of a sign that your body isn’t in a proper ketogenic state.

Objective Measurements:

Now we have looked at how you can feel and measure subjectively on a keto diet, let’s look at the objective measurements.

There are three main ways for you to test your ketone body levels all which test for different ketone bodies:

  • Urine- The urine strips are the easiest and cheapest way to measure for ketosis. These strips are only testing for the ketone body acetoacetate. This means that after the first few weeks of being on a keto diet, the strips can become unreliable. The main reason for this is the acetoacetate is eventually converted into one of the other ketone bodies (known as beta-hydroxybutyrate). After a while you may find that you get a negative reading on these sticks, even though your body is burning fat

Pros: cheap, easy, non-invasive

Cons: Non-reliable after a period of time, doesn’t measure the ketone body that the body mainly uses.

  • Blood– The next way to test is through the blood. This measurement is testing for the ketone body beta-hydroxybutyrate. This ketone body is the main one that the body will use for energy and so measuring ketosis through the blood is seen as the gold standard for testing. The strips to test for this can be really expensive and it does require you pricking your finger to get a blood sample so not great for people who are slightly squeamish.

Pros: Gold standard for ketosis level, accurate

Cons: More invasive, expensive

  • Breath- The newest method to market are breath meters with the only commercial one available called Ketonix. This measures for the ketone body known as acetate. This type of measurement hasn’t been 100% validated meaning the readings may sometimes be off. That being said, I have sampled with this myself and the newest meter is pretty accurate.

Pros: Less invasive, one off payment

Cons: technology hasn’t been fully scientifically validated

N.B.  Whenever you are measuring your ketone levels always measure in the evening  before  bedtime  and  first thing in the morning.

I hope that quick round up has helped to explain how and when you should test for ketosis in the body. I would love to know if any of you do measure objectively for ketosis and what results you are getting?

  • Doc

    Hi. I’ve been eating low carb constantly since March 28 and I’ve been measuring my breath Acetone levels, which are in the Ketogenic range (4 PPM+). I’m having daily headaches and fatigue still. Could this still be my body switching to fat burning? I’ve heard it can take 6-8 weeks to become fully fat adapted.