Is measuring blood ketone level necessary for ketogenic diet?

Is measuring blood ketone level necessary for ketogenic diet?

As ketogenic diet becomes increasingly popular and approachable, different methods of achieving ketosis have appeared. Terms such as, “lazy keto,” “dirty keto,” “clean keto”, or “strict keto”, have already spread widely in the ketogenic diet community. Each of these keto methods still target low-carbohydrate daily consumption (typically, 20-50g carb/day), but some are more casual in their approach than others. As ketogenic diets become increasingly personalized, we consider in this article the importance of measuring blood ketone levels while following a ketogenic diet.

Regulated keto involves careful tracking of “macros”, the shortened term for macromolecules, to control from which macromolecules your calorie intake comes from: fat, carbohydrate, and protein. In ketogenic diets, the proportion of calories coming from fat will certainly be the highest, typically at approximately 70-80%. However, the goal of ketogenic diet is not only to lower carbohydrate consumption and increase fat intake. The main objective is to achieve ketosis. The only way to know for certain that the body is in ketosis is to check ketone levels.

Regulated ketogenic diet has many health benefits.

Knowing when exactly the body is actively using its fat for metabolism allows the best chances of consistently staying in ketosis. Cycling in and out of ketosis may involve a handful of unwanted symptoms, which is collectively referred to as the “keto flu.” It is, especially, a safe approach compared to other “casual” methods. The optimal range for blood ketone level is between 0.5 to 3 mmol/L. Measuring ketone levels prevents the danger of entering ketoacidosis, a dangerous, and even perhaps a deadly, condition in which ketone levels become too high and the body blood pH turns overly acidic. Staying in the desired range of nutritional ketosis also means higher chances of effective weight loss. Tracking ketosis may also motivate those pursuing the diet to continue it for a longer term.

Blood ketone levels is known to be the most accurate way to know whether the body has achieved ketosis.

There are 3 common ways of testing ketone levels in the body: breath, urine, and blood. Each respectively measures acetone, acetoacetic acid (AcAc), and beta-hydroxybutyric acid (BHB), three different types of ketone body. Ketone bodies are breakdown products during metabolism of fatty acid, which becomes the primary source of fuel when carbohydrates are deprived.

Since BHB is the most prevalent type of ketone body, accounting for approximately 78%, its measurement is able to provide the most accurate reading into how much ketones are produced in the body. Most urine dipsticks measure acetoacetate. The problem with using urine is that it often underestimates the amount of ketone actually present, which may result in false negatives. Both urine and breath testing have external factors that may distort the accurate understanding of the presence of ketones in the body. The level of hydration, depending on the volume of water intake and exercise, may vary the concentration of ketones in the urine. Breath acetone measurement is becoming a popular alternative. However, further studies are needed to confirm that breath acetone is able to accurately reflect a wide range of ketone levels actually present in the body with no significant real-time lapse.

Blood ketone measurement is being made more accessible and affordable to all its potential users. By allowing the dieters to know when and how their body responds to certain foods, exercise, fasting, and different ranges of macros, it acts as a useful guide on their track of both safely and effectively achieving and continuing in ketosis.


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- Moore, A.R., Holland-Winkler, A.M., Ansley, J.K. Boone, E.D.H., & Schulte, M.K.O. (2021).Reliability and diagnostic performance of a new blood ketone and glucose meter in humans. Journal of the International Society of Sports Nutrition, 18(6).
- Gibson, A. A., Eroglu, E. I., Rooney, K., Harper, C., McClintock, S., Franklin, J., Markovic, T. P., Seimon, R. V., & Sainsbury, A. (2020). Urine dipsticks are not accurate for detecting mild ketosis during a severely energy restricted diet. Obesity science & practice, 6(5), 544–551.
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- Ruzsanyi, V., Kalapos, M.P. (17). Breath acetone as a potential marker in clinical practice. Journal of Breath Research, 11(2), 024002. 1088/1752-7163/aa66d3



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