Intermittent Fasting and Drunk Driving Charges in North Carolina

Intermittent fasting has gained popularity for a range of personal and medical reasons, from weight management and metabolic health to religious observance and athletic discipline. While it may offer certain physiological benefits, fasting also triggers changes in the body’s metabolic pathways that may complicate the interpretation of forensic alcohol testing in DWI cases.

This can become relevant in North Carolina, where the outcome of driving while impaired charges hinge on the reliability of breath or blood alcohol test results.

Defense attorneys, prosecutors, judges, and forensic experts are occasionally called to consider whether intermittent fasting affects the body’s internal chemistry and the resulting reported BAC.

Does fasting result in the production of ketones, acetone, and other compounds that could interfere with breath or blood testing technology? Does ketogenesis affect the BAC?

This informal analysis examines whether intermittent fasting could possibly produce ketone bodies that interfere with electrochemical fuel cell breath testing or gas chromatography-mass spectrometry (GC-MS) blood analysis, potentially creating false positive results or complicating the interpretation of test results in North Carolina DWI cases.

When science and law converge in complex DWI cases, experience matters. Powers Law Firm regularly helps clients facing serious impaired driving charges throughout Mecklenburg, Iredell, Union, Gaston, Lincoln, Rowan, and Stanly Counties. For cases involving significant consequences, including Felony Death by Vehicle, Misdemeanor Death by Vehicle, and Felony Serious Injury by Vehicle charges, we review charges in jurisdictions throughout North Carolina on a case-by-case basis. If you’re facing DWI charges where the science matters as much as the law, we invite you to call or text 704-342-4357 for a confidential consultation.

Intermittent Fasting and Ketone Production: The Biochemical Foundation

Intermittent fasting induces a metabolic state wherein the body shifts from glucose metabolism to fat oxidation, resulting in the production of ketone bodies.

This process, known as ketogenesis, occurs in the liver when glycogen stores become depleted, typically after 24 hours (or more) of fasting.

The liver converts fatty acids (triglycerides)  into three primary ketone bodies: acetoacetate, beta-hydroxybutyrate (BHB), and acetone.

During intermittent fasting, ketone levels rise progressively with fasting duration.

After a single overnight fast, concentrations of ketones in the body can be around 0.1 – 0.5mM, meaning the subject may be just below the “threshold” for ketosis. After 36 hours of fasting, ketones can reach 1 – 2mM.

The smallest ketone body, acetone, presents particular significance for alcohol testing because it is volatile and exhaled through the breath, where it could, at least potentially, interact with breath testing devices.

The production of acetone during fasting follows a predictable biochemical pathway.

Acetoacetate, the primary ketone body produced by the liver, undergoes spontaneous decarboxylation to form acetone.

Unlike BHB and acetoacetate, which serve as energy substrates for peripheral tissues, acetone cannot be metabolized for energy and is eliminated primarily through exhalation.

This excretion pathway places acetone directly in the analytical path of breath-based alcohol detection systems used in NC drunk driving charges.

One important issue is whether the specific breath testing devices in North Carolina, relative to DWI charges, those being (primarily) the AlcoSensor FST and the Intoximeter EC/IR II, detect, measure, and/or account for such substances.

Acetone-to-Isopropanol Conversion in Intermittent Fasting: A Critical Metabolic Pathway

There is some level of concern regarding forensic alcohol testing not from acetone itself, but from its potential conversion to isopropanol within the body.

Under certain circumstances, acetone may be reduced in the body to isopropanol by hepatic alcohol dehydrogenase (ADH).

This enzymatic reduction occurs when the ratio of reduced nicotinamide adenine dinucleotide (NADH) to its oxidized form (NAD+) is elevated, a condition that can occur during periods of metabolic stress, including extended fasting.

Clinical evidence supports this metabolic conversion.

Obviously, there are substantial differences between individual subjects.

Unless the defendant facing DUI charges is closely monitoring both their glucose levels and performing ketone testing (via blood) during a +24-hour fast, one will never truly know whether that has taken place.

Certain athletes and diabetic and pre-diabetic subjects may, in fact, monitor both their glucose and ketone levels on a regular (documentable) basis.  For the legal practitioner, it makes sense to ask, “Are you diabetic, on a keto diet or other restricted carbohydrate diet or do you intermittent fast?”

While certain studied cases involved diabetic ketoacidosis, it demonstrates the body’s capacity to convert acetone to isopropanol under conditions of elevated ketone production when induced by means other than Type 1 or Type 2 diabetes (irrespective of the causality pathway.)

Endogenous acetone, produced during ketosis, can be converted in the body to isopropanol.

Some breath testing devices, particularly those using electrochemical fuel cell sensors, may respond to isopropanol as if it were ethanol.

This cross-reactivity can affect results under certain (relatively rare) metabolic conditions.

Interference with Electrochemical Fuel Cell Breath Testing

Electrochemical fuel cell technology, the predominant method used in evidential breath testing devices in North Carolina DWI cases, operates by oxidizing ethanol at an electrode surface to produce an electrical current proportional to alcohol concentration.

However, these devices exhibit varying degrees of specificity for ethanol versus other alcohols.

The inexpensive models that people buy for self-checking their BAC are largely inaccurate and therefore unreliable.

In legal proceedings, the greater concern arises with older or less advanced breath testing devices, which are more likely to misinterpret certain compounds, such as acetone or its byproducts, as ethanol.

By contrast, modern instruments that combine fuel cell analysis with infrared (IR) detection are generally more capable of identifying and filtering out ketones, reducing the risk of false readings caused by metabolic conditions like ketosis or diabetes.

The specificity of fuel cell devices varies significantly. While manufacturers claim ethanol specificity, In 2006, Dr Alan Jones did a research paper on ignition interlock devices. He looked at the case of a man who was on a low carb diet. He could not start his car, that was fitted with an ignition lock device. This documented case demonstrates real-world interference from dietary ketosis with alcohol detection technology.

Law enforcement agencies’ continued use of older equipment compounds this issue. While newer breathalyzer technology has improved in distinguishing isopropanol from ethanol, many law enforcement agencies still use older devices, increasing the potential for incorrect DUI charges. This technological heterogeneity creates uncertainty in the reliability of breath test results when subjects are in ketosis.

Implications for GC-MS Blood Testing

Gas chromatography-mass spectrometry represents a more reliable standard for forensic alcohol analysis, offering superior specificity compared to breath testing methods.

GC-MS separates compounds based on their physical and chemical properties before identifying them through mass spectral analysis.

This dual separation and identification process theoretically eliminates the cross-reactivity issues plaguing simpler analytical methods.

In many North Carolina DUI cases, laboratory analysis relies solely on gas chromatography (GC), without completing the mass spectrometry (MS) phase of GC-MS. Even certified labs that regularly testify in court often perform only the initial separation step, leaving compound identification based on retention time alone rather than full molecular confirmation.

As such, the presence of endogenous compounds related to ketosis can still complicate GC-MS analysis.

Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and individuals demonstrating that acetone is a normal metabolic product that should appear in biological samples.

For GC-MS blood analysis, the primary concern involves proper peak identification and quantification.

While GC-MS can distinguish ethanol from compounds like acetone and isopropanol using both retention times and mass spectra, that level of analysis depends on whether full mass spectrometry is actually performed.

In practice, the presence of endogenous alcohols or related metabolites requires deliberate interpretation, which is often skipped or abbreviated.

Many, if not most forensic labs conducting DUI testing in North Caroilna rely on gas chromatography alone.

That’s not a good thing.

The mass spectrometry phase is time-intensive, not well-suited to batch processing, and frequently omitted, even by labs that routinely testify in criminal court.

For DUI defense lawyers, this raises a concern that goes beyond methodology.

When the prosecution presents chemical evidence while bypassing the more accurate and confirmatory phase of GC-MS, questions of reliability and fairness inevitably follow.

Precision and analytical rigor should not be optional when someone’s liberty is at stake.

Endogenous Ethanol Production During Intermittent Fasting

Beyond ketone-related interference, intermittent fasting may influence endogenous ethanol production.

The concentration of endogenous ethanol in plasma has showed wide inter-subject variations ranging from below detection limits to 1.6 micrograms/ml (34.8 mumol/l).

While these levels fall far below legal intoxication thresholds, they demonstrate the body’s capacity for ethanol production.

Research on diabetic patients provides insight into metabolic conditions that elevate endogenous ethanol.

In one study, the BAC in the group of patients with diabetes mellitus (n = 130) was significantly higher (mean value 2.65 mg/L) than in the control group (mean value 0.40 mg/L).

Although such concentrations likely remain legally insignificant, they establish that metabolic states affecting carbohydrate metabolism can influence endogenous ethanol levels.

The gut microbiome can also play an important role in endogenous ethanol production.

During fasting states, alterations in gut bacterial populations and substrate availability may influence fermentation patterns.

However, the concentrations of endogenous ethanol in the peripheral venous blood of healthy individuals, as well as those afflicted by specific metabolic conditions (diabetes, hepatitis, and cirrhosis), may not surpass 0.08 mg/dL, well below the legal threshold of 80 mg/dL (0.08 g/dL) in North Carolina.

Quantitative Considerations and Legal Thresholds

The quantitative aspects of ketone production during intermittent fasting desere careful consideration in appropriate DWI fact patterns.

While acetone levels normally increase during fasting, the question remains whether these levels can produce legally significant interference with alcohol testing.

While ketosis can produce detectable levels of acetone and potentially isopropanol, these rarely reach concentrations that would register as legal intoxication or “impairment” in NC.

The situation becomes more complex for motorists with ignition interlock devices, the “blow and go.”

If you blow .02 or higher BAC, you’ve likely violated the terms and conditions of interlock compliance.

At lower thresholds, ketosis-related interference becomes more plausible and therefore legally significant.

Forensic and Legal Implications

The potential for intermittent fasting to influence alcohol testing results creates several challenges for the legal system.

Defense attorneys need to understand the science sufficiently to identify when metabolic interference might have affected test results.

Prosecutors and law enforcement must take reasonable steps to ensure their testing protocols account for potential confounding factors.

Several key considerations emerge for legal practitioners:

1. Device-Specific Vulnerabilities: Older fuel cell devices and ignition interlock systems appear more susceptible to interference than modern evidential breath testing instruments or full GC-MS blood analysis for BAC – Blood Alcohol Concentration.

2. Individual Metabolic Variation: The degree of ketosis achieved through intermittent fasting can vary significantly among individuals, influenced by fasting duration, metabolic rate, and adherence to carbohydrate restriction.

3. Temporal Factors: The timing of testing relative to fasting periods affects ketone levels. Peak acetone production typically occurs after extended fasting periods, normally after 24-hours or more of strict “water only” fasting.

4. Confirmation Testing: Blood testing via GC-MS provides superior specificity and should be requested when breath test results may be compromised by metabolic factors.

Recommendations for DWI Defense Lawyers

For defense attorneys representing clients who practice intermittent fasting, several strategies merit consideration:

Documentation: Maintaining records of fasting schedules and dietary practices may help provide essential context for challenging test results.

Expert Testimony: Forensic toxicologists familiar with metabolic interference can explain the scientific basis for questioning test reliability, obviously when appropriate.

Alternative Testing: Requesting blood analysis when breath tests may be compromised can ensure more accurate results.

Device Records: Examining maintenance and calibration records for testing devices may reveal susceptibility to interference.

For prosecutors and law enforcement, awareness of these metabolic factors should inform testing protocols and the interpretation of results, particularly in cases involving individuals known to follow restrictive dietary practices.

It helps if DWI defense lawyers remain informed about metabolic considerations in DWI cases.

As intermittent fasting and other metabolic interventions become increasingly popular, the affects of dietary practices and forensic science will likely receive continued attention from both the scientific and legal communities.

Understanding these complex interactions serves the fundamental goal of accurate and fair adjudication in cases where chemical testing may serve as a fundamental and central aspect of evidence against the accused.

While the scientific foundation is solid, it’s important to understand this represents an uncommon defense scenario rather than a frequent occurrence in DWI cases in North Carolina – Bill Powers, NC DWI Lawyer

North Carolina DWI Defense Lawyers: Powers Law Firm

Intermittent fasting can potentially produce metabolic changes that potentially interfere with alcohol testing, primarily through the production of acetone and its conversion to isopropanol.

While certain metabolic products rarely reach levels that would cause false positive results at legal intoxication (impairment) thresholds, they may create complications for lower-threshold devices such as ignition interlocks and certain breath testing equipment such as PBT – Portable Breath Test.

Scientific evidence indicates that modern evidential breath testing devices and GC-MS blood analysis can generally distinguish between ethanol and ketone-related compounds.

However, use of older and/or less reliable technology and the individual variation in metabolic responses to fasting create ongoing challenges for the accurate determination of alcohol consumption.

In serious DWI cases, the science doesn’t sit in the background, it’s often the fight.

Whether the issue is breath testing, blood analysis, or what a lab report really proves, we think it helps to understand how these systems work and where they break down.

Powers Law Firm represents clients facing impaired driving charges across Mecklenburg, Union, Iredell, Gaston, Lincoln, Rowan, and Stanly Counties. In cases involving Felony Death by Vehicle, Misdemeanor Death by Vehicle, or Felony Serious Injury by Vehicle, we consider statewide representation on a case-by-case basis.

If you’re facing charges where what the lab did or didn’t do may change the outcome, call or text 704-342-4357. The consultation is confidential. The stakes are real. So is the work. 📍 Find Powers Law Firm on Google Maps