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Blood Sugar Lies: Why Your Morning Glucose Might Be Telling the Wrong Story

InsulinJourney / 28 May 2025 /

Hi, I’m Alex — founder of InsulinJourney, and someone who reversed insulin resistance without medication by testing, learning, and applying real-world data. In this article, I want to bust one of the biggest myths I believed for too long: that a “normal” morning glucose means you’re in the clear.

The Myth of “Normal” Morning Glucose (Fasting Blood Sugar)

When I first measured my fasting glucose, I got numbers like 4.9 mmol/L (88 mg/dL) and thought I was fine. But I was gaining weight, constantly tired, and felt mentally foggy. I had no idea that I was deep into insulin resistance and creeping toward prediabetes.

What you measure in the morning is often just a snapshot — and it might be hiding the real problem.

The Dawn Phenomenon: A Natural Spike That Can Confuse You

Take a look at this real example from my own CGM (Continuous Glucose Monitor):

This is around 4:00–5:00 a.m. I’m still asleep. Glucose is low and stable at ~4.8 mmol/L (86 mg/dL).

Now at 06:05 — I’m still in bed, but my cortisol levels start rising. Glucose hits 4.9 mmol/L (88 mg/dL).

Fifteen minutes later? Boom — 6.2 mmol/L (112 mg/dL). I haven’t eaten a thing. That’s cortisol in action. If I had measured my glucose right then, I might think I had prediabetes or even type 2 diabetes.

This is called the dawn phenomenon, and it’s normal to a point. But if it stays high, or keeps climbing after breakfast, that’s a red flag.

Why Fasting Glucose Isn’t Enough

Glucose levels are dynamic, and morning blood sugar doesn’t capture how your body handles real life: stress, food, poor sleep, and more. I’ve had perfect fasting numbers, but massive post-meal spikes. That’s hidden insulin resistance in action.

Why CGM Is the Best Mirror for Metabolic Health

Using a CGM taught me more in 14 days than years of blood tests. Here’s what I learned:

  • My “healthy” banana smoothie = spike to 8.5 mmol/L (153 mg/dL)
  • Late-night snack = wrecked sleep and high fasting glucose
  • Strong black coffee = instant cortisol + glucose spike
Person A vs Person B: Who’s Really Healthier?

Person A:

  • Fasting glucose: 5.2 mmol/L (94 mg/dL)
  • But after lunch, spikes to 9.0 mmol/L (162 mg/dL) and stays high for 2 hours

Person B:

  • Fasting glucose: 6.0 mmol/L (108 mg/dL)
  • But stable glucose all day: 4.5–6.5 mmol/L (81–117 mg/dL)

Person C (new):

  • Fasting glucose: 5.4 mmol/L (97 mg/dL)
  • But 30 min after oatmeal breakfast: 10.1 mmol/L (182 mg/dL), then crashes to 3.5 mmol/L (63 mg/dL)

Guess who’s most at risk? It’s Person A and C, not B.

What Should You Track Instead?

Instead of a single fasting number, I now look at:

  • Average glucose over 24h (aim: ~5.2 mmol/L or 94 mg/dL)
  • Post-meal peaks (aim: below 7.8 mmol/L or 140 mg/dL)
  • Time-in-range (3.9–7.8 mmol/L or 70–140 mg/dL)
  • Glucose variability (spikes = inflammation)

These are the true markers of metabolic health.

The Role of Sleep, Light, and Stress

Poor sleep and artificial light wreck my morning glucose. I’ve learned that:

  • Scrolling at midnight raises cortisol and delays melatonin
  • Under 6h sleep = fasting glucose goes up by 0.5–1.0 mmol/L (9–18 mg/dL)
  • Evening stress = elevated glucose through the night

Sleep is metabolic therapy.

What to Ask Your Doctor (And What to Watch Out For)

Unfortunately, many doctors still rely on outdated metrics. Here’s what I recommend asking for:

  • Fasting insulin (goal: under 5 µIU/mL)
  • HOMA-IR index (ideal < 1.0)
  • HbA1c
  • Kraft Glucose/Insulin Challenge Test

But don’t stop there. Ask yourself:

  • Is my doctor fit, energetic, and metabolically healthy?
  • Does he/she practice what they preach?
  • Has this doctor helped others reverse insulin resistance?

Look for real-world success stories, not just credentials.

Practical Tips From My Own CGM Journey
  • Don’t test glucose right after waking. Wait at least 30–60 minutes
  • Try 14 days of CGM. Eat as usual. Track the spikes.
  • Prioritize: sleep, morning light, walking post-meals, and stress management
  • Don’t panic over one number. Look at patterns.
Final Thought: Listen Beyond the Numbers

Morning glucose alone isn’t a diagnosis. It’s a clue. Real metabolic health is revealed in your patterns, responses, and habits. Your CGM can be your best teacher.You can follow my experiments and insights through the IJ Pulse newsletter or join our real-time discussions on Telegram: @insulinjourney

If you want a structured approach to improving your blood sugar and energy, check out the IJ Method coaching program. We cover glucose, hormones, CGM, sleep, supplements, and more — all grounded in data and real-world testing.

Alex Oleinik

I’m an entrepreneur, YouTuber, and creator of the Insulin Journey Method. My mission is to help people boost their energy, optimize their health, and build a sustainable lifestyle through science-backed strategies.

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