Measuring Ketosis Using Urine
Ketones can be used to fuel the body. The body will use glucose first for energy as long glucose is available. The body will burn fat in the form of ketones when the diet is low in carbohydrates (complex of glucose). How can you tell if your body is producing ketones so that you can monitor your success or progress following the ketogenic diet? We discussed in earlier posts that you can test for ketones in the blood and also use the glucose-ketone index to determine your level of ketosis. But, guess what? You can also measure ketones in your urine.
Ketone urine strips are inexpensive and easy to use. Noticing changes in color and smell of your urine could be a tip-off that you are in ketosis. An even better indicator is a change in your breath, but this article focuses on urine.
Three types of ketones are produced by the body: acetone, acetoacetate, and beta-hydroxybutyrate. Urine keto strips only test for acetoacetate.
Does Ketosis Change Your Urine or Make it Dark?
Being in ketosis will change the color and odor of your urine and is a good indication that you are having success on a keto diet. Urine becomes clearer initially when on a keto diet. This is because in the early stages of ketosis the body is depleting glycogen which is a storage form of carbs. For one part of glycogen, there are 4 parts of water. So as you deplete glycogen you also rid yourself of the water tied to those glycogen molecules.
Urine color will change in appearance as you go from pre-ketosis to ketosis. These stages are:
- dark yellow
- oily yellow
We discussed the reasons for clear urine but what about the other changes in urine that occur in ketosis?
When in ketosis you will start burning stored-up fat-releasing metabolites stored in fat such as acetoacetate which is oily. Urine is not frothy but when on a keto diet you will produce more urine and will urinate with more force causing the water in the toilet bowl to bubble up. Dark yellow urine simply means you are not consuming enough water on your keto diet. You should drink more water throughout the day.
Does Your Pee Smell in Ketosis?
It depends on what you mean by “smell”. “Smell” usually implies a bad odor, but if you mean does your urine have a different odor or smell than normal (for you) while on a keto diet, then the answer is “yes” if you are in ketosis. Urine often smells sweet and fruity when in ketosis.
What Color is Your Urine When in Ketosis?
See section above and below, “Does Ketosis Change Your Urine or Make it Dark?” Changes in urine go through stages the longer one stays in ketosis.
Ketosis Urine Color Chart
- Clean Urine
- Dark Yellow Urine
- Frothy Urine
- Oily Urine
Ketosis Urine Color Green
Green urine many times is caused by medications that may contain a blue phenol that when it mixes with yellow urine produces the color green.
Does Ketosis Make Your Body More Acidic?
Eating a ketogenic diet could make your body more acidic but it does not necessarily lead to any significant pH changes. pH is a measure of acidity or alkalinity. A pH scale goes from 0 to 14. pH is a measure of hydrogen ion concentration. A pH greater than 7 is considered basic or alkaline and a pH less than 7 is considered acidic. Normal blood pH is 7.35 to 7.4. Therefore, the pH of blood is typically alkaline. While the pH of the urine can change significantly by what we eat the pH of the blood is more tightly regulated and the body has several physiological mechanisms to keep blood pH slightly alkaline. Part of this includes the respiratory and renal systems. For instance, hyperventilation will raise the pH by blowing off carbon dioxide. The kidneys are charged with removing excess acid from the body. In addition, calcium from the bones buffers the acid it needed.
Below are the usual pH ranges in various parts of the body.
- Skin pH is 4 to 6.5
- Stomach pH is 1.35 to 3.5
- Bile pH is 7.6 to 8.8
- Vaginal pH is 4.7 or less
- Venous blood pH is 7.35
- Arterial blood pH is 7.4.
Animal meats tend to be acidic and if consumed as part of a ketogenic diet can lower urinary pH but not so much blood pH for reasons stated above. Alkaline diets are high in healthy whole foods like fruits and green vegetables which can be consumed on a keto diet but in small amounts since they are carbs.
What Should Urine Ketone Levels Be for Ketosis?
When you begin to see a change in urine color or smell then you should check your urine for ketones to confirm that you are actually in ketosis.
The results from a urine test for ketones will either come back negative/normal or abnormal/positive. “Abnormal” is a relative term because if you are on the ketogenic diet you want ketones to show in your urine. A negative test result means the ketone levels are normal for the individual something you don’t want to see if on a keto diet. An abnormal result means the test detected ketones in the urine. This result falls into three categories or levels:
- Small levels of ketones: Less than 20 mg/dL
- Moderate levels of ketones: Between 30 and 40 mg/dL
- High levels of ketones: Above 80 mg/dL
The level of ketosis in the section above is expressed in mg/dl but levels can be expressed mmol/L
- Small levels of ketones: less than 1.5 mmol/L
- Moderate levels of ketones: 4.0 mmol/L
- High levels of ketones: 8.0 mmol/L
- Very high levels of ketones: 16.0 mmol/L
For weight loss, you will want to have urine ketone levels at least in the 1.5 mmol/L to 3.0 mmol/L range.
You will want to test your urine for ketones in the morning after fasting overnight. It is also helpful to test after meals which will help you determine if certain foods are knocking you out of ketosis.
Urine pH can also be tested using pH test strips.
One value that can be measured in the urine is known as urine pH. pH is a measure of the acidity or alkalinity of a substance. If the pH is low, then it is acidic. If the pH is high, then it is basic, or alkaline.
Normal urine pH is roughly 4.6-8, with an average of 6. Urine pH can increase, meaning it will become more basic, or alkaline, due to:
- A urinary tract infection
- Kidney failure
- The administration of certain drugs such as sodium bicarbonate
- Vegetarian diets
On the flip side, causes for a decreased, or acidic, urine pH, include:
- Metabolic or respiratory acidosis
- Diabetic ketoacidosis, a complication of diabetes mellitus
- High-protein diets
Since fasting (a milder form of starvation) and higher protein intake on a keto diet compared to a typical diet a keto diet can cause urine to become more acidic.
How Long Does it Take for Ketones to Appear in Urine?
Ketones can show up in the urine following an overnight fast even when not on a ketogenic diet. This would be more true for someone who does overconsume carbs and is not on the keto diet. Conversely, one high carbohydrate meal can throw you out of ketosis.
Can Ketones In Urine Cause Burning?
No, ketones when present in your urine do not cause burning. Burning with urination could be a sign of a urinary tract infection. If you experience burning be sure to see your doctor.
How Accurate are Ketosis Urine Strips?
Keto urine strips are strips of paper with a small pad at end of one end of the strip that changes color when dipped in urine or when you pee on them. They’re similar to urine pregnancy strips in that regard as well as urine pH strips. Keto urine strips are sometimes called ketone sticks.
Urine keto strips typically turn varying degrees of red, pink, or purples. The darker the color the more ketones in the urine.
They are accurate but their accuracy depends on your state of hydration. If you are over hydrated the strips will underestimate the presence of ketones in the urine and if you are dehydrated they will overestimate the number of ketones in your urine.
The strips are accurate enough to tell you whether or not you are in ketosis. Urine testing is not as accurate as blood testing for ketones. Also, the longer you are on a keto diet the better your body adapts to using ketones better for fuel. This means the more ketones that are used for fuel the less the number of ketones will be present in the urine. This is important to keep in mind. Also, there are breath monitors than can detect ketones but the most accurate way to test for ketones in the body is through blood tests.
Can keto urine strips be wrong?
Yes, they can be wrong. We alluded to the fact that the longer you have been in keto the less likely acetoacetate will show up in your urine as your body adapts to using ketones for energy. Once the container is open and exposed to air keto strips will start to go bad. The container will usually tell how long the strips are good for – usually 30 to 90 days. When you may want to write the “expiration date” on the container once you open the container for the first time.
Can keto urine strips go bad?
Yes, keto urine strips can go bad. They generally are good for 30 to 90 days once the container has been opened and the test strips exposed to air.
Best Ketosis Urine Strips?
According to this review, the best ketone test strips are KETO MOJO, Perfect Keto, One Earth Health, Nurse Hatty, and JNW Direct. Other reputable test strips are considered SmackFat, ReliON, Keto-Doc, Zenda Naturals, and Kiss my Keto.
Where Can I Buy Ketosis Urine Strips?
Keto urine strips are readily available at drugstores, grocery stores, and online. They are relatively inexpensive. Typically you can buy 50 to 100 strips in a box or container. A container of 100 strips might cost $10. Urine strips go bad after 90 days in most cases so be aware of that. Strips should be stored with lid closed tightly and the container in a cool, dry place.