About Ketosis

What is Ketosis?


Ketosis is a metabolic state where the body utilizes fat stores for energy, in contrast to a state of glycolysis, where blood glucose provides energy.  Most people in the developed world are regularly in a state of glycolysis.

However, when blood glucose from carbohydrates and simple sugar sources cannot meet cellular energy demands, the body forms ketone bodies from fat tissue and subsequently utilizes these ketone bodies for energy.This is considered being in a ketogenic state or in a state of ketosis, commonly referred to as “fat burning”. 

Ketosis is a desirable state for many people interested in weight-loss, specifically loss of body fat.  Ketosis is also of interest to diabetics for blood sugar control and has shown therapeutic evidence for many other health-related concerns. A ketogenic state can be achieved through dramatically reduced carbohydrate intake and exercise.

Note:  METRON® is not indicated for the diagnosis or management of diabetes or any other conditions or diseases.


Why do I need to test to see if I am in a state of ketosis?

Maintaining a steady state of ketosis optimizes fat utilization for energy and thus “fat burn” or “weight loss”.

A ketogenic state can be affected by several factors, including level of caloric intake, type of caloric intake (i.e. carbohydrate/sugar vs. protein vs. fat), and level of physical activity. 

Due to variability in the metabolisms of individuals, achieving a ketogenic state may require different dietary and physical activity levels for different people.  Furthermore, the relatively strict regimens required to maintain a state of ketosis may be difficult for some people to closely adhere to.  Frequent, efficient and accurate testing can help determine if your behaviors are resulting in a ketogenic state and that your fat burn is optimized.  This is one reason why the METRON® Breath Ketone Test is so useful!

How do I test to see if I am in a state of ketosis?

Recent developments in analysis technology have allowed for rapid, efficient and accurate ketogenic testing utilizing breath. The METRON® Breath Ketone Test from Akers Bio uses patented technology to measure breath acetone. 

The standard and most accurate measurement for ketone bodies is a blood test, however it requires a blood sample via finger prick or blood draw, which may not be a convenient or preferred method of testing, particularly when frequent tests are desired. 

Currently, the most widely available test for at-home use is the urinary dipstick ketone test.  However, urinary levels of ketone bodies do not necessarily correlate to blood levels of ketone bodies and a state of ketosis (Gilbert et al 2000). Urine testing can be unreliable due to the changes in ketone ratios produced by the body and the decrease of ketones excreted into the urine (referred to as ketoadaption) the longer your body is in a ketogenic state (Marliss et al 1970). 







(Click infographic to view larger image)


How can ketosis be measured from my breath?

When you are in a state of ketosis your body is producing ketone bodies from stored fat to utilize as energy.  Humans produce three types of endogenous ketones:
    1. Acetoacetic acid
    2. Beta-hydroxybutyrate
    3. Acetone

            Acetone is an organic compound that diffuses quickly from the blood stream to the lungs and is expelled in the breath. By utilizing chemical color change, acetone levels can be quantitatively measured in breath, and a level of approximately 5 ppm (parts per million) indicates a state of ketosis.


            How accurate is breath testing for ketosis?

            As low carbohydrate diets designed to put the user in a steady state of ketosis have grown in popularity, so has the demand for a method to efficiently, accurately, and conveniently evaluate a person’s ketogenic state. Several clinical studies have been conducted to evaluate breath analysis, in comparison to the benchmark blood ketone tests. Breath analyses for acetone, such as with the METRON® Breath Ketone Test has shown to be strongly correlated and a strong predictor of ketones in blood plasma for individuals on a ketogenic diet (footnote: R2 = 0.70, P < .0001, Musa-Veloso et al 2002) (R2 = 0.99, P < .0001, Musa-Veloso et al 2006).


            A state of ketosis is one where a body breaks down body fat for energy (e.g. a fat-burning state).  Ketosis can be affected by several factors, thus it is important to evaluate your ketogenic state regularly if fat loss is your goal.

            Although urinary dipstick ketone tests are inexpensive, urine-based ketosis tests may become unreliable over time for multiple reasons.  Additionally, many people may find both the urine and blood testing processes to be unpleasant. In contrast, breath acetone test such as Metron® is simple and convenient, and provides accurate analysis of ketones, even over time.

            Links to additional information about ketosis:



            Gilbert DL, Pyzik PL and Freeman JM (2000) The Ketogenic Diet: Seziure Control Correlates Better With Serum beta-Hydroxybutyrate Than With Urine Ketones. J Child Neaurol, 15:787-790.

            Marliss EB, Aoki TT, Unger RH, Soeldner JS and Cahill GF (1970) Glucagon levels and metabolic effects in fasting man.  J of Clin Inves, 49(12): 2256-2270. ketosis. (n.d.) Mosby's Medical Dictionary, 8th edition. (2009).

            Musa-Veloso K, Likhodii SS, Rarama E, Benoit S, Lie YC, Chartrand D, Curtis R, Carmant L, Lortie A, Comeau FJE and Cunnane SC (2006) Applies nutritional investigation: Breath acetones predicts plasma ketone bodies in children with epilepsy on a ketogenic diet.  Nutrition, 22(1):1-8.

            Musa-Veloso K, Likhodii SS and Cunnane SC (2002) Breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals.  Am J Clin Nutr, 76:65-70.