Ketogenic diet therapy should be monitored to achieve effective results. There are three different methods for checking and monitoring ketosis. I’ll explain each then give examples of how my patients have selected the one to suit their needs.
Urine ketones (acetoacetate) is the simplest and cheapest but least accurate of all methods. This method may be “good enough” for people who are monitoring themselves at home and are able to get a more specific level at their doctor’s office. This is not precise because it measures the ketones that are cleaned out of the blood by the kidneys. It's a measurement of past, not current ketosis. Another reason that its considered a "crude" metric of ketosis is that the amount of liquid that you drink can change the reading. If you are drinking very little an hour before you check, the urine ketone reading can appear strong on the test stick. If you are drinking a lot before you check, the ketones can appear weak because they are diluted. In this scenario, your ketones could be strong in the bloodstream but show up as weak in the urine.
Example: I’m working with a 5-year-old who started on ketogenic diet therapy over a year ago for epilepsy. Our plan was to start with the simplest method of checking ketones, and, if needed, we’d graduate to a more precise method for better seizure control. After three months on the diet his seizures stopped completely, no diet changes were needed and so there was no reason to change to the method of checking ketones.
Products: there are only a few different companies that make urine ketone test strips. The One Earth Health brand is the most reasonably priced (shown above). My patients like the color chart on the bottle which shows an estimate of the blood ketone betahydroxybutrate (in mmol/L) along with the urine reading.
Blood ketones (betahydroxybutryate) is a metric that has an advantage over urine ketones in that it reveals ketosis in real time and is not affected by the amount of liquid that you drink. The betahydroxybutryate (or BOHB for short) level can be correlated to blood glucose which can be helpful in adjusting the diet. The lower the blood glucose, the higher the BOHB level. For this reason most of my patients prefer to check both levels simultaneously. If you are taking exogenous ketones of salts or esters that are primarily the L-BOHB, the meter will not detect that version.
Example: An adult client of mine, who is using ketogenic diet therapy as a complimentary treatment for her brain cancer, uses a meter to check ketones and glucose. Tracking both metrics over time has helped us to modify her diet to achieve consistency in lowering her glucose and achieving stronger ketones.
Products: there are only a few companies that make a meter that can check both glucose and ketones. Meters are generally inexpensive but the disposable strips can be cost prohibitive. Many of my clients have chosen KetoMojo because the strips are less costly. Their meter also reads hemoglobin and hematocrit levels which other meters don’t do.
The third method is monitoring ketones from exhaled breath called acetone. This device evaluates ketones released from the lungs captured by breathing into a tube.
Example: An athletic client with diabetes prefers this method of monitoring ketosis in addition to checking his glucose. He found that breath acetone was more consistent than a blood level of betahydroxybutrate which decreased during exercise but increased later.
There are currently 2 companies that make portable acetone breath analyzers. My patients prefer the KEYTO brand for its ease of use with an APP.