Your body may be making extra insulin just to keep your blood sugar in the normal range.
When cells become less responsive to insulin, the pancreas can compensate by producing more. For a time, that extra insulin may keep glucose levels looking normal. A glucose monitor shows the resulting glucose pattern, but it cannot tell you how much insulin was needed to produce it.
In the Metabolic Classroom, Dr. Ben Bikman explores how continuously measuring glucose and ketones together could add another layer of information. The technology has an immediate application in diabetes care, along with broader possibilities for studying how the body responds to meals, fasting, and changes in fuel availability.
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What the New Glucose and Ketone Sensor Measures
On August 25, 2026, the FDA authorized Abbott’s Libre Duo 10 Day system for people with diabetes ages two and older. It is the first wearable authorized in the United States to continuously monitor ketones, and the first system worldwide to continuously measure glucose and ketones together in one device.
The sensor measures both substances in interstitial fluid—the fluid surrounding cells beneath the skin—every minute for up to ten days. Readings go to a compatible smartphone, where users can see trends and receive alerts about concerning ketone levels.
That continuous view addresses a limitation of traditional ketone testing: a measurement only happens when someone decides to take one.
Why Continuous Ketone Monitoring Matters
Blood ketone meters provide a useful snapshot of beta-hydroxybutyrate, usually shortened to BHB. Urine strips measure a different ketone, acetoacetate, while breath meters measure acetone. Because these tests measure different molecules, their readings do not necessarily rise and fall together.
This is particularly relevant during diabetic ketoacidosis. Urine testing can underestimate ketone buildup early on and remain elevated during recovery, even as blood BHB falls. Blood BHB testing gives a more direct assessment of the ketone most relevant to that process.
Continuous monitoring adds information between those individual tests. It can reveal whether ketones are rising, falling, or staying elevated while someone is asleep or occupied with daily life.
How Insulin Regulates Ketone Production
Dr. Bikman describes insulin as a brake on ketone production. Insulin suppresses the release of fatty acids from stored fat, reducing the supply available to the liver. It also regulates processes within the liver that influence whether those fatty acids enter the pathways used to produce ketones.
As insulin falls during fasting or carbohydrate restriction, that restraint can ease. More fatty acids become available, and the liver can increase ketone production to help supply energy to other tissues. This relationship is central to the physiology of ketosis.
This is why ketones interest researchers studying insulin and metabolic health. Their rise and fall can provide information about how the body is responding to changing fuel availability.
What Ketone Readings Mean
A ketone reading cannot be translated into an insulin level.
The amount of BHB present reflects both how quickly ketones enter circulation and how quickly tissues use them. Food intake, physical activity, other hormones, and ketone supplements can all influence the result. Ketone supplements, for example, can raise BHB without requiring the body to produce those ketones from stored fat.
Ketone trends can therefore offer indirect clues about insulin’s influence on fuel metabolism. Interpreting those clues requires context, including what someone has eaten, their activity, their medications, and their health status.
Nutritional Ketosis and Diabetic Ketoacidosis
That context also explains the distinction between nutritional ketosis and diabetic ketoacidosis, or DKA.
During nutritional ketosis, the body produces ketones in a regulated way while maintaining normal blood acidity. DKA develops when insufficient insulin and other hormonal changes allow excessive ketone production, leading to metabolic acidosis—a dangerous increase in acidity.
DKA can occur even when glucose is near normal. This is especially relevant for people taking SGLT2 inhibitors, a class of glucose-lowering medications. A reassuring glucose reading does not rule out a developing ketone emergency.
For people at risk, symptoms such as vomiting, abdominal pain, or rapid breathing require urgent medical attention. A sensor does not measure blood acidity, and concerning symptoms should not be dismissed because its readings appear reassuring.
Earlier awareness of rising ketones could be particularly valuable during illness, after missed insulin, or when an insulin pump stops delivering properly. The opportunity is to identify a concerning trend sooner and act according to an established care plan.
What This Could Mean for Metabolic Health
Beyond diabetes safety, Dr. Bikman is interested in what paired glucose and ketone patterns might reveal about everyday metabolism.
Following both signals could help researchers examine how ketones change after different meals, during fasting, and around exercise. Those observations may deepen our understanding of metabolic flexibility—the body’s ability to adjust fuel use as conditions change.
There is still much to learn. Researchers do not yet have well-established reference patterns for continuous ketone readings across everyday life. The dual sensor is not an established diagnostic test for insulin resistance or metabolic flexibility, and a higher ketone number is not a universal measure of better metabolic health.
The new sensor makes it possible to observe two connected metabolic signals together over time. Understanding what those patterns mean will depend on the physiology Dr. Bikman explains in this lecture: how insulin regulates fuel availability, how the liver produces ketones, and how the body’s needs change throughout the day.