“I'm a diabetic, FYI.”

Why is my fasting blood sugar high? A type 2 diabetic's guide to reducing Dawn Phenomenon

Friday, July 12, 2019

Jason Tu
By Jason Tu

Photo by @sgabriel on Unsplash.
Photo by @sgabriel on Unsplash.

So you’ve gotten your diabetes under control.

You’ve eliminated refined carbs from your diet. No more breads, pastas, cereals, waffles for you.

You’ve started working out.

Maybe you’ve even started doing this intermittent fasting thing, and refrained from eating for periods of time.

You’re doing diabetes management right! You got this!

And yet, when you measure your blood sugar upon waking up, your meter shows the highest blood sugar reading of the day: perhaps it’s a big, ugly, a-little-high 136 mg/dL:

A 136 mg/dL fasting blood sugar. Kinda high...
A 136 mg/dL fasting blood sugar. Kinda high...

You might think: what the heck? I didn’t eat anything since dinner last night.

Don’t be discouraged. High fasting blood sugars are a common problem among type 2 diabetics, and there’s a name for it: Dawn Phenomenon. Luckily, there are a few strategies we can use to reduce its intensity, and keep our blood sugar under tight control.

What’s a Dawn Phenomenon?

Dawn Phenomenon is something that everyone experiences, regardless of whether you’re a diabetic. Between 2 and 8 AM, your body secretes more growth hormone, cortisol, glucagon, and epinephrine to prepare you for the day ahead. Apparently, this surge of hormones raises your blood sugar.1

In a non-diabetic, the body counters this hormone soup (and resultant rise in blood sugar) by secreting more insulin. As a result, the blood sugar remains steady.

However, a type 2 diabetic is insulin deficient: either the cells resist insulin, and do not respond properly, or a type 2 diabetic simply doesn’t produce enough insulin anymore due to beta cell burnout. Either way, there’s less working insulin to counter the rise in blood sugar.

In his post about Dawn Phenomenon, Dr. Jason Fung likens the rise in blood sugar to “taking a dump” – that is, your liver is dumping sugar!2

An apt, but unsavory analogy.
An apt, but unsavory analogy.

If you’re a diabetic and you own a continuous glucose meter (CGM), you can also observe this phenomenon for yourself. Here’s a graph of one of my more severe Dawn Phenomenon days:

Dawn Phenomenon captured on a FreeStyle Libre, on a day when my first meal was at 5 PM. Note that my Libre reads 20 points lower than actual blood sugars.
Dawn Phenomenon captured on a FreeStyle Libre, on a day when my first meal was at 5 PM. Note that my Libre reads 20 points lower than actual blood sugars.

Okay, what can I do about it?

It seems that not many people know how to manage Dawn Phenomenon. If you search online, you’ll find conflicting advice:

  • Eat a snack containing carbs before bedtime
  • Eat a snack containing protein before bedtime
  • Don’t eat a snack before bedtime, and eat dinner early
  • Eat upon waking to stimulate insulin production
  • Take medication or insulin before bedtime (I don’t take meds or insulin, so I can’t make judgments about their effectiveness)

There may be some valid science behind strategic snacking to stimulate certain hormones. But overall, I find that none of the points above really helped.

What I have found helpful, is to remember the earlier analogy:

Dawn Phenomenon is your liver dumping sugar.

So if you minimize the sugar in your liver (also known as glycogen), there’ll be less sugar to dump. That principle leads us to 3 strategies:

Strategies

  1. Measure your carb and protein intake, and reduce it.
  2. Exercise strategically.
  3. Replace breakfast with fat.

Measure your carb and protein intake, and reduce it

If you aren’t already logging your meals in a food logging app, you should start! Logs allow you to track your carb, protein, and fat intake:

I particularly like Cronometer (https://cronometer.com/), which has an extensive food database.
I particularly like Cronometer (https://cronometer.com/), which has an extensive food database.

Examine your carb and protein consumption. If you find that your morning blood sugars are higher than you’d like, reduce your daily carb allowance. Experiment to see if that improves your morning blood sugars over time.

If you find that your morning blood sugars are still high, reduce your protein intake as well. Remember: carbs and excess protein get stored as glycogen in your liver, and glycogen is what turns to blood sugar in the morning.3

That doesn’t mean starving yourself, of course! Even under a strict carb and protein allowance, you can choose nutrient-dense foods like leafy greens and pasture-raised eggs to keep your body satiated.

Exercise strategically

I find that an evening workout tends to lower peak blood sugar the next morning. The catch is that the evening workout has to be sufficiently intense to burn off excess glycogen.

A graph of my blood sugar the day after a tougher evening run. Note the lower peak reading from Dawn Phenomenon, compared to an earlier graph.
A graph of my blood sugar the day after a tougher evening run. Note the lower peak reading from Dawn Phenomenon, compared to an earlier graph.

Another strategy is to exercise immediately upon waking up, to counteract the rise in blood sugars from Dawn Phenomenon.

Either approach works well. It would depend on whether you’re a morning person or a night owl.

Replace breakfast with fat

It goes without saying: if your morning blood sugars are high, you should avoid eating breakfast to prevent pushing your sugars out of range.

If you have to eat breakfast, you could try eating fat. Dietary fat doesn’t affect your blood sugar, isn’t stored as liver glycogen, and won’t add to the blood sugar rise from Dawn Phenomenon:

Butter is delicious! Look for grass-fed butter in your local grocery.
Butter is delicious! Look for grass-fed butter in your local grocery.

The keto world packages many solutions for fat consumption. If you like coffee, try bulletproof coffee (which is coffee infused with butter and MCT oil).

Fat bombs turn dietary fat into fun snacks, but you should look for recipes with no added carbs or protein, since you want to avoid affecting your blood sugar levels during the Dawn Phenomenon period.

Every diabetic is different

Every diabetic has different levels of insulin resistance, beta cell burnout, stress, inflammation, and more. So a plan that works for one diabetic, might require some tweaking for another diabetic.

Regardless, I hope you’ve found the principles above to be helpful. What other strategies have you discovered to reduce Dawn Phenomenon? Please leave a comment below – I’d love to hear your tips and tricks!