Ketones in Urine – How To Test and What Levels Are Optimal
There are likely two reasons you want to test the ketone levels in your urine:
REASON 1 – you’ve got type one diabetes (or type two diabetes, in some cases) and you need to test the ketones levels in your urine to help you avoid ketoacidosis.
If that’s the case, skip down to the sections on…
Then, skip straight to the section on…
REASON 2 – you’re on the Keto diet and you want to use urine strips to check if you’re in ketosis.
If that’s the case, then don’t worry we’ll also cover:
- What ketones are…
- Why you’d want test the ketone levels in your urine (and how to do it),
- Best method to test your ketone levels, plus
- What ketone levels you should be looking for.
But skip the section on ketoacidosis – it doesn’t apply to you unless you’re diabetic!
Note that information contained in this article (and website) is not intended to and shall not convey or recommend any medical or nutritional advice or course of action. Any diet, health, or nutritional program you undertake should be discussed with your doctor or other licensed medical professionals. All opinions expressed in this article are based solely on personal experiences and research. We are NOT licensed doctors, dietitians, or nutritionists.
What are ketones?
First things first – a quick 101 intro on what ketones actually are:
Ketone bodies (or ketones) are produced by your liver during the break down of fatty acids when your body is low on glucose. Your body then uses these ketone bodies as fuel.
Some of your cells can’t directly use the fatty acids in your fat stores to produce energy.
And that’s because those fatty acids are unable to pass through the membrane which surrounds those cells.
And if they can’t get inside? They can’t be used as fuel.
So there’s an extra step to the process:
First, the fatty acids travel to your liver where they’re broken down into ketones. And as these ketone bodies are smaller and water-soluble, they’re able to enter your cells.
Which means your cells can use these ketone bodies as a source of energy.
The ketone bodies produced by your body:
And to get even more technical, ketones are a class of water-soluble organic molecules with a very specific chemical structure.
However, when people talk about ketones for nutritional ketosis purposes on the ketogenic diet, they’re usually referring to a few specific ketones produced by our body as fuel (and these are technically called ketone bodies).
According to Diapedia.org, “In healthy adults, the liver is capable of producing up to 185g of ketone bodies per day.”
And these ketone bodies typically come in 3 different forms:
This is found mostly in your urine.
This is found mostly in your blood (it’s technically not a ketone but a carboxylic acid because it has a different chemical structure, but it’s commonly referred to as a ketone, and your body converts it to one of the previous two molecules before your cells use it).
This is found mostly in your breath.
What are ketones in urine?
How do ketones end up in your urine?
ANSWER: Ketones end up in your urine when your body can’t use them…
This can happen because:
- Your body isn’t adapted to using ketones yet – which happens when you first start a keto diet.
- Your body is producing dangerous levels of excess ketones – which is only a danger for diabetics, there are more details on that in the next section
How do you measure ketones in urine?
This is super straightforward to do using urine testing strips/sticks (often called by the brand name of Ketostix).
Cost: These cost approximately $25 for 100 strips (or sticks). So they’re fairyly cheap.
Advantages: These ketone urine strips are cheap and easy to use.
Disdvantages: They’re really not very accurate in measuring your body’s ketone levels.
How to use: And all you do is you pee on these sticks, which have a certain chemical covered on them that can detect the levels of acetoacetate in your urine.
These sticks will change color depending on the level of ketones in your urine:
If the Ketone urine strips don’t change color…
If they don’t change color, then no ketones are detected in your urine. Your body is not in ketosis.
If the Ketone urine strips turn a dark purple…
If a dark purplish color results on your ketostix, then “high” levels of ketones are detected in your urine.
If you’re on the Keto diet, then this could be a useful indicator that you’re in nutritional ketosis.
Ketoacidosis and high ketones in urine
Before we dive into this, a side note…
If you don’t have diabetes, then Keto won’t give you ketoacidosis!
According to Registered Nurse, Debra Sullivan, PhD, RN, “The breakdown of fat for fuel and the creation of ketones is a normal process for everyone. In a person without diabetes, insulin, glucagon, and other hormones prevent ketone levels in the blood from getting too high.”
“However,” she adds, “people with diabetes are at risk for ketone buildup in their blood.”
Your body has natural feedback mechanisms, involving insulin, that prevents this from happening in people without diabetes.
So keep calm! Mother Nature has your back.
But if you have type 1 diabetes (and in some rare cases, type 2 diabetes), then you will need to be aware of ketoacidosis.
For all the diabetics, we’re going to jump into this important topic and break it down. This is something that mostly only affects type 1 diabetics and very rarely some type 2 diabetics.
Ketoacidosis can result when your body doesn’t get enough insulin to let glucose in your blood into your cells. This prompts your body to think that it’s short on glucose (since there’s very little in your cells).
And because your body thinks there’s very little glucose in your body, it starts producing ketones as an alternative fuel source.
This, unfortunately, means you end up with very high blood ketone levels at the same time as very high blood sugar levels. When you have type 1 diabetes (and for some people with type 2), your body’s usual warning system is broken, so your blood ketone levels keep rising causing your blood to become too acidic. This can result in comas and even death. So, please be very aware of this condition if you have diabetes.
In non-diabetic folks, a high concentration of ketones in the bloodstream triggers the release of insulin.
This causes three things to happen…
- Fat cells stop releasing fatty acids to the liver, so your liver “runs out” of fatty acids to turn into ketones,
- The speed with which the liver produces ketones is significantly decreased, and
- Ketones are taken out of the blood stream and moved into the urine.
Which all results in ketone levels dropping back into a normal range.
But if your body doesn’t produce insulin?
Your ketone levels just keep going up…
…and up and up, to dangerously high levels.
Regular insulin injections are what it takes to prevent this from happening and to lower increased ketone levels back to normal range.
So if you are diabetic (type 1 in particular) and are seeing increased levels of ketones in your urine, then this could be a sign to take care with your insulin injections and seek medical advice.
Should you test for ketones in urine?
Before you all rush off to buy ketone urine testing sticks –
Bear this in mind:
Urine Testing of Ketone Levels Isn’t Very Accurate
It only tells you about the ketones which are removed from your bloodstream and end up in your urine.
But Testing of Ketone Levels in Urine Can Be Useful In These Cases:
- If you have type 1 diabetes and you’re testing for ketones in urine to prevent ketoacidosis – And all you need is a rough indicator.
- If you’ve just started a keto diet and want to to get a rough idea of if you’re doing it correctly.
Word of Caution For Keto Dieters Measuring Ketones In Urine
When you first start a Keto diet, your body won’t have adapted to using ketones yet, so it will excrete most of them in your urine.
Certified Keto Coach Lori Ballen says, “The urine strips to measure for ketones are fine in the beginning to simply test if your body is producing ketones. The presence of ketones do not mean your body is using them. It may take a few days to a few weeks for your body to become keto-adapted and use the ketones properly.”
So when you use the ketone urine sticks to measure for them, you’ll see the sticks turn dark. And you’ll get excited that your Keto diet is working and you’re in nutritional ketosis!
But be aware that this is only a measure of the ketones that are excreted from your body…it is NOT a measure of the ketones that are in your blood and circulated for use by your cells.
Anyone who’s been keto for a while might actually see their ketones in urine decrease.
Your body will be making ketones and using them up. So your urine ketone levels will likely be quite different from your blood ketone levels.
But if you’re still using the ketone urine strips to measure your ketone levels, then you might be worried that something has gone wrong with your diet!
That’s why if you want to test for ketones, then there are much more accurate methods…
Other Methods Of Testing For Ketones Are More Accurate
If you want a more accurate way to test your ketone levels…
Try using a blood ketone monitor
How to use: You prick your finger and put a drop of blood on the test strip. Then insert the test strip into the blood ketone meter/monitor and it’ll produce a digital reading of your blood ketone levels.
This meter also measures blood glucose levels (but you’ll need to buy different strips to measuring glucose levels – those are typically much cheaper).
Advantages: These provide a very accurate measurement of your blood ketone levels. They’re the method used in medical studies on keto diets.
Disadvantages: The main downside to these blood ketone monitors is how expensive the strips are. So use them sparingly!
“So who needs one of these gadgets?” asks Dr. Andreas Eenfeldt, M.D. “Perhaps nobody. Obviously it’s easy to eat [low carb high fat] without it. This is for curious nerds (like me) and for those who want definite proof that they are eating so little carbs that insulin levels are low and fat burning is maximized.”
Which is a much more accurate way to tell if you’re in ketosis or not.
Or try using a breath ketone meter
Cost: These breath ketone meters are made by Ketonix and are reusable. But they are quite an expensive investment at over $200.
How to use: You basically blow into the meter and it gives you a digital reading. Ketonix has more detailed instructions here.
Advantages: These are easy to use (no pricking of fingers) and produce pretty accurate results.
Disdvantages: You have to spend a lot of money upfront on these meters.
What’s the optimal levels of ketones you should be aiming for on a Keto diet?
There is no hard-and-fast rule for this, because…
The optimal blood ketone level depends on your goals.
Dr. Stephen Phinney, M.D., from Virta Health says, “[Nutritional Ketosis] is characterized by concentrations between 0.5 and 2 mmol/L for most people consuming a [whole food ketogenic diet], which typically consists of a variety of nutrient-rich foods with some carbs (e.g., non-starchy vegetables, olives, nuts/seeds).”
Most Keto experts agree: If you want to lose weight…Aim for a ketone level above 0.5 mmol/L.
Looking to improve exercise performance? Again, aim for a ketone level above 0.5 mmol/L.
Need to boost mental performance? Then aim for 1.5 – 3 mmol/L.
And if you’re using the keto diet for therapeutic purposes? (e.g. to treat epilepsy) Then you might need higher ketone levels of 3 – 6 mmol/L. But make sure to work with a medical practitioner on this.
But don’t get too hung up on your ketone levels!
There’s no need to try and chase super high ketone levels if you don’t really need them to meet your goal.
You need to leave room in your diet for essential protein, vitamins, and minerals.
So don’t feel pressured to ramp up your fat intake in order to boost your ketones.
What matters is your results and not your ketone level!
Here’s a quick recap of our key takeaways…
If you’re a Keto dieter…
Testing of ketones is optional, and you can choose which method you use.
If everything’s going well and you’re seeing the results you desire?
Don’t worry about testing ketone levels!
Just keep doing what you’re doing.
But if you want to be reassured you’re in ketosis and troubleshoot your diet?
Then testing ketone levels could be a good idea. Urine testing is okay if you’ve only just started keto.
But if you’ve been keto for a while? Or you’re only aiming for lower ketone levels?
Then testing your blood ketone levels is a better, more accurate option. And the optimal ketone level for you really depends on your goals on Keto (see the previous section for more details).
And you don’t have to be scared about getting ketoacidosis, either.
And if you have type 1 diabetes…
Testing ketones in your urine gives you a rough indicator of your ketone levels.
It should be enough to establish if they’re in a healthy range or if they’re too high.
And if you do find you have high ketone levels?
Then you should seek medical attention. Ketoacidosis is a serious issue which needs immediate treatment. And don’t worry, it’s reversible when caught in time!