Your fasting glucose is 105 mg/dL.

Your doctor says, "You're pre-diabetic. Watch your carbs."

But you've been carnivore for 3 months. You eat zero carbs. How is your glucose still elevated?

Here's what your morning glucose actually means, why it might stay high on carnivore, and when you should worry.

What is Insulin Resistance?

Insulin resistance is when your cells stop responding to insulin's signal to take in glucose.

Your pancreas produces insulin. Insulin tells your cells: "Absorb glucose from the bloodstream."

When cells are insulin resistant, they ignore the signal. Your pancreas pumps out more insulin to compensate. Eventually, blood sugar stays elevated because insulin can't force it into cells.

End result:
  • High fasting insulin (hyperinsulinemia)
  • High fasting glucose (hyperglycemia)
  • Type 2 diabetes (when your pancreas can't keep up)

Insulin resistance is driven by:

1. Chronic carbohydrate consumption

2. Excess calories (overeating)

3. Inflammation (seed oils, processed foods)

4. Sedentary lifestyle

5. Chronic stress and poor sleep

Carnivore eliminates 1, 2, and 3. But it doesn't instantly reverse decades of metabolic damage.

Your Morning Glucose: What's Normal?

Optimal fasting glucose:
  • 70-85 mg/dL = excellent metabolic health
  • 86-99 mg/dL = normal, slightly elevated
  • 100-125 mg/dL = pre-diabetic range
  • 126+ mg/dL = diabetic (requires medical intervention)

Most carnivores land in the 70-90 mg/dL range after 3-6 months.

But some carnivores see fasting glucose in the 95-110 mg/dL range despite zero carbs. Why?

Physiological Insulin Resistance (Adaptive Glucose Sparing)

When you eat zero carbs for weeks, your body adapts. It shifts into a mode called physiological insulin resistance.

Here's what happens:

1. Your Muscles Become Insulin Resistant (On Purpose)

Your muscles prefer fat and ketones for fuel. They downregulate glucose uptake to spare glucose for your brain.

This is adaptive. Your brain needs 20-30g of glucose per day (produced via gluconeogenesis from protein). By making your muscles insulin resistant, your body ensures your brain gets enough glucose.

2. Gluconeogenesis Ramps Up

Your liver produces glucose from protein (gluconeogenesis). This keeps your brain fueled without carbs.

If your liver is producing 30-40g of glucose per day and your muscles aren't absorbing it (because they're using fat), fasting glucose stays slightly elevated.

3. Dawn Phenomenon

Your body releases cortisol and growth hormone in the early morning to wake you up. Both hormones raise blood sugar by triggering gluconeogenesis and glycogen breakdown.

On carnivore, this effect is amplified because you're already in a low-insulin state.

Result: Fasting glucose of 95-110 mg/dL, even though you're metabolically healthy.

How to Tell If It's Adaptive or Pathological

Not all elevated fasting glucose is benign. Here's how to differentiate:

Test 1: Check Your Fasting Insulin

Fasting glucose alone doesn't tell the full story. You need fasting insulin.

Healthy (physiological IR):
  • Fasting glucose: 95-110 mg/dL
  • Fasting insulin: < 5 μIU/mL
  • HOMA-IR: < 1.0
Pathological (true insulin resistance):
  • Fasting glucose: 100-120 mg/dL
  • Fasting insulin: 10-20 μIU/mL
  • HOMA-IR: > 2.0
HOMA-IR formula:

(Fasting insulin × Fasting glucose) ÷ 405

Interpretation:
  • < 1.0: Excellent insulin sensitivity
  • 1.0-1.9: Normal
  • 2.0-2.9: Early insulin resistance
  • 3.0+: Significant insulin resistance

If your fasting insulin is low (< 5 μIU/mL) and glucose is 95-110 mg/dL, you're fine. It's physiological.

If your fasting insulin is high (> 10 μIU/mL), you still have pathological insulin resistance. Keep going.

Test 2: Oral Glucose Tolerance Test (OGTT)

Drink 75g of glucose. Measure blood sugar at 1 hour and 2 hours.

Healthy response:
  • 1 hour: < 140 mg/dL
  • 2 hours: < 120 mg/dL
Insulin resistant response:
  • 1 hour: > 160 mg/dL
  • 2 hours: > 140 mg/dL

If you spike high but return to baseline quickly, your insulin is working. If you stay elevated at 2 hours, you're still insulin resistant.

Test 3: Continuous Glucose Monitor (CGM)

Wear a CGM (Freestyle Libre, Dexcom) for 2 weeks. Track your glucose 24/7.

Healthy pattern:
  • Stable glucose: 70-100 mg/dL all day
  • Small post-meal spikes (10-20 mg/dL)
  • Tight glucose range (low variability)
Insulin resistant pattern:
  • Erratic swings: 80 → 130 → 90 throughout the day
  • Large post-meal spikes (30-50 mg/dL)
  • High variability (glycemic instability)

If your CGM shows flat, stable glucose despite slightly elevated fasting levels, you're metabolically healthy.

Test 4: HbA1c (3-Month Average)

HbA1c measures average blood sugar over the past 3 months.

Targets:
  • < 5.0%: Optimal
  • 5.0-5.6%: Normal
  • 5.7-6.4%: Pre-diabetic
  • 6.5%+: Diabetic

If your fasting glucose is 105 mg/dL but your HbA1c is 5.0%, your average glucose is fine. The morning spike is just gluconeogenesis.

Why Your Glucose Might Stay High on Carnivore

Reason 1: You're Still Reversing Insulin Resistance

Insulin resistance doesn't reverse overnight. It took years to develop. It takes months to fix.

Timeline:

  • Month 1-2: Insulin drops, glucose starts dropping
  • Month 3-6: Fasting glucose normalizes for most people
  • Month 6-12: Stubborn cases resolve

If you're 3 months in and fasting glucose is 105 mg/dL, you might just need more time.

Reason 2: You're Eating Too Much Protein

Excess protein converts to glucose via gluconeogenesis. If you're eating 250g+ protein per day, your liver is cranking out glucose.

Solution: Moderate protein to 1g per lb of bodyweight. Increase fat intake.

Reason 3: Chronic Stress and Poor Sleep

Cortisol raises blood sugar. If you're sleeping 5 hours a night and stressed out, your fasting glucose will stay elevated.

Solution: Sleep 8+ hours. Manage stress. Meditate, walk, cut back on caffeine.

Reason 4: Dawn Phenomenon

Cortisol spikes in the early morning (4-8 AM). This raises glucose via gluconeogenesis.

Test your glucose at different times:

  • 6 AM: 110 mg/dL
  • 10 AM: 85 mg/dL

If it drops after waking, it's just cortisol. Not a problem.

Reason 5: You're Still Eating Hidden Carbs or Inflammatory Foods

Dairy, protein bars, "carnivore-approved" snacks with fillers, or restaurant food with seed oils can keep insulin resistance active.

Solution: Go strict. Beef, salt, water for 30 days. Retest.

Reason 6: Genetic Predisposition (APOE4, MTHFR)

Some people have genetic variants that make them hyper-responders to dietary fat or prone to elevated LDL and glucose.

If you've done everything right and glucose stays high, get genetic testing (23andMe, AncestryDNA, then upload to Promethease).

Solution: Work with a functional medicine doctor to optimize for your genetics.

When to Worry

Red flags:
  • Fasting glucose > 110 mg/dL for 6+ months on strict carnivore
  • Fasting insulin > 10 μIU/mL
  • HOMA-IR > 2.0
  • HbA1c > 5.7%
  • Post-meal glucose spikes > 140 mg/dL (if you test after protein meals)
  • Symptoms: fatigue, brain fog, weight gain despite calorie deficit

If you have 2+ red flags, investigate further:

  • Full thyroid panel (TSH, Free T3, Free T4, Reverse T3)
  • Cortisol (morning and evening)
  • Sex hormones (testosterone, estradiol, DHEA)
  • Liver function (ALT, AST)

Sometimes elevated glucose is secondary to thyroid dysfunction or adrenal issues, not insulin resistance.

How to Lower Fasting Glucose on Carnivore

Step 1: Reduce Protein Slightly

If you're eating 250g+ protein, cut to 150-180g. Increase fat to maintain calories.

Example:
  • Before: 24 oz lean beef (250g protein, 50g fat)
  • After: 16 oz ribeye (120g protein, 120g fat)

Retest in 2-4 weeks.

Step 2: Add Fasting

Fasting lowers insulin and improves insulin sensitivity.

Start with 18-hour fasts (2 meals per day). Work up to OMAD or 48-hour fasts weekly.

Step 3: Improve Sleep

Sleep 8+ hours. Fix your sleep hygiene:

  • Dark room, cool temperature (65-68°F)
  • No screens 1 hour before bed
  • Magnesium glycinate before bed (400mg)
Step 4: Reduce Stress

Chronic stress = chronic cortisol = elevated glucose.

Strategies:

  • Walk daily (lowers cortisol)
  • Meditate 10 minutes/day
  • Cut caffeine after 12 PM
  • Limit intense exercise (overtraining raises cortisol)
Step 5: Lift Heavy (Build Muscle)

Muscle is your glucose sink. More muscle = better insulin sensitivity.

Train 3-4x/week. Focus on compounds: squat, deadlift, bench, rows.

Step 6: Test and Track

Get bloodwork every 3 months:

  • Fasting glucose
  • Fasting insulin
  • HbA1c
  • Lipid panel (optional)

Track trends over 6-12 months. You should see steady improvement.

The Bottom Line

Your morning glucose tells a story, but only if you read the full chapter.

Fasting glucose 95-110 mg/dL + low insulin (< 5 μIU/mL) = physiological insulin resistance. This is normal on carnivore. It's adaptive. Not pathological.

Fasting glucose 95-110 mg/dL + high insulin (> 10 μIU/mL) = pathological insulin resistance. You're still reversing metabolic damage. Give it more time. Optimize sleep, stress, and protein intake.

Don't panic over a single number. Look at the full picture: insulin, HbA1c, HOMA-IR, symptoms, and trends over time.

And remember: Carnivore is reversing decades of damage. Healing takes time.

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References:
  • Kraft JR. Diabetes Epidemic & You. Trafford Publishing. 2008. (Kraft Insulin Assay data)
  • Phinney SD et al. The human metabolic response to chronic ketosis without caloric restriction. Metabolism. 1983.
  • Paoli A et al. Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. Eur J Clin Nutr. 2013.
  • Volek JS, Phinney SD. The Art and Science of Low Carbohydrate Living. Beyond Obesity LLC. 2011.