Thomas DeLauer has been adding apple cider vinegar to his fasting routine for years, but recent research has him doubling his dose.
The reason? New findings suggest that the acetic acid in ACV activates the same metabolic switches that fasting does—except it flips them harder.
While ramping up fat burning in your liver, it simultaneously quiets hunger signals in your brain. Two opposite effects working in perfect harmony during a fast.
In a recent video, DeLauer broke down the surprisingly specific mechanisms behind apple cider vinegar’s metabolic punch and shared his updated protocol for using it strategically throughout a fast.
Jump to:
- Why Apple Cider Vinegar Hits Your Liver First
- Fat Burning Gets Switched On, Fat Storage Gets Shut Down
- The Nighttime Apple Cider Vinegar Hack for Blood Sugar
- Why Apple Cider Vinegar Shuts Off Hunger in Your Brain
- How to Actually Use Apple Cider Vinegar During a Fast
- Why This Works During Fasting Specifically
Why Apple Cider Vinegar Hits Your Liver First
When you drink apple cider vinegar, something interesting happens before your body does anything else with it. Acetic acid gets absorbed and shuttled directly to your liver.
Once there, it converts into acetyl coenzyme A—a process that actually costs energy. Your liver burns ATP and converts it into AMP, shifting what’s called your AMP-to-ATP ratio inside liver cells.
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That ratio shift triggers a cellular alarm: we’re in energy deficit mode.
This activates AMPK, often called the body’s “energy sensor” or “deficit switch.” When AMPK senses low cellular energy, it flips your liver from storage mode into full-on burning mode.
Because what that means is your liver, after a small dose of apple cider vinegar, essentially behaving like a liver in a deeper state of fasting than you’re actually in.
Research published in Biochemical and Biophysical Research Communications treated rat liver cells with acetate and found AMPK activation shot up within just one hour. Your liver essentially thinks you’re fasting harder than you actually are.
Fat Burning Gets Switched On, Fat Storage Gets Shut Down
Once AMPK activates in liver cells, downstream metabolic effects kick in—exactly what you want during a fast.
AMPK upregulates PPAR alpha, a gene controlling fatty acid oxidation. Think of PPAR alpha as the machinery that pulls fatty acids into mitochondria and torches them for fuel.
At the same time, AMPK shuts down SREBP-1c, the master switch for creating new fat in your liver. More fat burned, less new fat made.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
But there’s another layer. Apple cider vinegar appears to increase something called uncoupling protein 2 (UCP2), which dissipates energy as heat instead of capturing it as ATP.
Sounds wasteful, right? During a fast, it’s metabolic gold. Your body actively “wastes” energy as warmth, creating an inefficiency that forces more fat burning and increases thermogenesis.
Real Weight Loss in Humans Without Changing Diet
One 12-week study put this to the test with obese adults. Participants took either a placebo, 1 tablespoon of vinegar daily, or 2 tablespoons—without changing diet or activity levels.
- The 1 tablespoon group lost 2.6 pounds more than placebo
- The 2 tablespoon group lost 3.7 pounds more
- Triglycerides improved, though benefits plateaued quickly beyond 2 tablespoons
DeLauer notes that while 1 tablespoon does serious metabolic work, 2 tablespoons appears optimal for body composition. Beyond that, you’re not getting much additional benefit.
The Nighttime Apple Cider Vinegar Hack for Blood Sugar
Taking ACV before bed might be one of the most underrated fasting strategies, according to DeLauer. It targets something called the dawn phenomenon.
During overnight fasting, your liver doesn’t just sit idle. It runs gluconeogenesis—manufacturing glucose from fat and protein sources, then dumping that glucose into your bloodstream right around wake-up time.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
In healthy people, this is mild and helps you function in the morning. In insulin-resistant individuals, it causes a significant blood sugar spike even after 12+ hours without food.
AMPK activation in the liver puts the brakes on gluconeogenesis. It inhibits key enzymes and slows down that overnight glucose dump.
Diabetes Care Study Shows Real Fasting Glucose Drops
A study published in the Journal of Diabetes Care tested this directly. Subjects with insulin resistance and type 2 diabetes took either water or 2 tablespoons of apple cider vinegar before bed.
- The water group dropped fasting glucose by 2%
- The ACV group dropped it by 4%
- Subjects with worse baseline glucose control (starting at 7.2 mmol/L) saw drops up to 6%
The takeaway? The worse your overnight glucose dump, the more pronounced the dawn phenomenon, the more apple cider vinegar helps.
During a fast, this matters because every blood sugar bump pulls you out of that fat-burning state and kind of gently nudges you a little bit more back towards storage again.
Suppressing gluconeogenesis at night deepens the metabolic effect of your fast the following day.
Blunting Carbs After Breaking Your Fast
Apple cider vinegar also works powerfully around meals when you break your fast. Research gave subjects 50 grams of carbs from white bread alongside either a placebo or 1 gram of acetic acid in vinegar form.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
The acetic acid group’s blood glucose response dropped 31% lower than placebo. Same carbs, drastically different blood sugar spike.
ACV essentially functions as a glucose control tool both during fasting and around eating windows, taking metabolic pressure off your liver.
Why Apple Cider Vinegar Shuts Off Hunger in Your Brain
Here’s where things get fascinating. AMPK doesn’t behave the same way everywhere in your body.
In your hypothalamus—the brain region controlling appetite—AMPK does the exact opposite of what it does in your liver.
When hypothalamic AMPK goes high, you get hungry. It signals deficit mode and triggers ghrelin release, ramping up appetite and screaming at your brain to eat.
Fasting itself raises hypothalamic AMPK. That’s why fasting hunger can feel brutal until ketones kick in and start quieting those signals.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
But apple cider vinegar does something almost nothing else does: it activates AMPK in your liver while suppressing it in your brain.
More fat burning, less hunger. Fasting on its own gets one of those right, but ACV gets both, right?
You’re hitting opposing switches in exactly the directions you want during a fast. Your liver burns more fat, your brain stops nagging you to eat.
How to Actually Use Apple Cider Vinegar During a Fast
DeLauer’s updated protocol is built around strategic timing for maximum metabolic impact.
Dosing: 1 to 2 Tablespoons
- 1 tablespoon is the minimum effective dose for metabolic effects
- 2 tablespoons showed greater weight loss in the 12-week study
- Going beyond 2 tablespoons doesn’t appear to add significant benefit
Timing Strategies
Morning in a fasted state: Activates liver AMPK and deepens fat-burning mode.
Before bed: Suppresses overnight gluconeogenesis and blunts the dawn phenomenon. The diabetes care data strongly supports this timing for improving next-day fasting glucose.
Sandwiching your evening meal: Take 1 tablespoon right before your carb-containing dinner, then another 1 tablespoon 20-30 minutes after eating. You get glucose blunting from the meal plus overnight fasting benefits.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
During a fast for hunger control: Take it whenever hunger hits hardest. When you feel hungry, you’re burning fat—ACV helps you stay in that zone without white-knuckling through cravings.
Important Safety Notes
- Always dilute apple cider vinegar in water
- Use a straw to minimize contact with tooth enamel and reduce esophageal irritation
- If you’re on glucose-lowering medication, monitor carefully—ACV is effective enough to potentially drop blood sugar too low
Why This Works During Fasting Specifically
Apple cider vinegar amplifies fasting’s metabolic benefits without breaking the fast itself. It’s not providing calories or spiking insulin in any meaningful way.
Instead, it’s enhancing what fasting already does while compensating for one of fasting’s biggest downsides: relentless hunger.
- Activates liver AMPK for increased fat oxidation
- Boosts thermogenesis through UCP2 upregulation
- Suppresses new fat creation via SREBP-1c inhibition
- Reduces overnight glucose production
- Quiets hypothalamic hunger signals
All of these mechanisms stack on top of fasting itself, creating a multiplier effect rather than just an additive one.
I’ve been taking 1 Tbsp of this during a fast for years, but now with the new research, I’m going to take 2 Tbsp because this is genuinely surprising me.
DeLauer’s approach is grounded in recognizing that fasting works—but strategic supplementation with apple cider vinegar can push those benefits considerably further, especially for glucose control and appetite management.
The science shows ACV isn’t just folklore. It’s a legitimate metabolic tool with specific, measurable effects on liver metabolism, glucose regulation, and appetite signaling.
If you want something simple that actually works, this is one of the most effective tools I’ve used to build strength, conditioning, and endurance without needing a full gym setup.
- Full-body training with one weight using swings, squats, and presses
- Solid cast iron build that feels stable and lasts for years
- Comfortable grip that makes high-rep workouts easier to handle
For anyone serious about optimizing their fasting protocol, 1 to 2 tablespoons of apple cider vinegar—taken strategically before bed or during the fasting window—appears to be one of the simplest, most effective additions you can make.
