Dawn Phenomenon, Breakfast, Physical Activity and Diabetes

A couple of months ago, I wrote about the relentless hypos I was having at work. There have been days where my blood sugars have been bouncing up and down like a yoyo. The smallest insulin correction would be enough to send me plummeting within half an hour. My Libre would then show me rebounding after a hypo (and I now know that the Libre tends to pronounce movements in my BGLs). I would have the urge to correct it again, only to end up low once again. This seemingly vicious cycle made it impossible to obtain a steady line while I was at work and left me feeling exhausted at the end of the day.

The one thing I genuinely do miss about injections is that insulin sensitivity during physical activity was hardly an issue. I don’t remember having to pay half as much attention to my diabetes at work while I was on injections. I’ve felt very conscious of the number of times I’ve had to tend to diabetes in a day. Unlike a Lantus injection, my pump delivers basal insulin in tiny amounts throughout the day as I’m working. In addition to physical activity, dawn phenomenon and breakfast boluses are also thrown into my morning diabetes equation.

After a lot of trial, error, and notes in my diary, I finally feel as though I’ve got my mornings down pat in recent weeks.

The obvious one has been making sure that my basal rate is right. I cannot stress how difficult morning blood sugar levels are to manage if I do not wake up in range. No amount of correction seems to be able to fix them, and I end up really grumpy at 8am as I see my levels soaring after breakfast.

A couple of weeks ago, I noticed that my levels were climbing at around 3am each morning, warranting a change in overnight basal rates. Until that was fixed, I wasn’t able to properly focus on the mornings. Another thing I’ve learned is that my waking basal rate (when my liver begins dumping extra glucose) needs to run for at least a full hour before I wake up. Even a gap of 15 minutes is enough to screw up my morning basal test. Going on intuition seems to have done the trick in fine tuning the remainder of my morning basal rates.


Breakfast really has been a case of trial and error. I’ve learned that I do not need to subtract any carbohydrates from my breakfast insulin dose. Subtracting 5g from my breakfast dose is the difference between a post prandial result of 9mmol or a post prandial result of 15mmol. My pump will also add a correction dose to my breakfast bolus if my blood sugar level is over 7mmol. 


I’ve learned that I need to ignore it unless my blood sugar level is above 8mmol, and that I need to subtract insulin accordingly if my blood sugar is lower than 6mmol.

Morning coffee at work normally happens anywhere between 8.30 and 9am. My medium cappuccino with no sugar probably has around 15g of carbs, 10g of which I do not need to bolus for. It’s been so hard to wrap my head around these tiny insulin doses, but they are indeed enough! Pre bolusing is also not necessary, as I slowly sip my hot coffee when it first arrives.

Morning tea comes anywhere between 10 and 11am, and is usually a banana which is weighed before I leave home. Again, bolusing for 10g less carbs seems to do the trick, as do the rules for correcting.

Not foregoing what I love in the mornings has been really important to me. It would have been easy to simply forego breakfast or the morning coffee, but I know that would have made me unhappy (and hungry!). I work diabetes around my life and my activity, and not the other way around.

It’s been a lot of hard work, but I do genuinely feel that I have my mornings down pat. Instead of going up and down multiple times in a day, it might happen 2 or 3 times in a week. Levels are also looking great, thanks to continued pre bolusing and my moderate carb approach. I plan on taking a break from my Libre after today, and I’m quite confident that I will be able to manage just fine on finger sticks for a while.

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8 thoughts on “Dawn Phenomenon, Breakfast, Physical Activity and Diabetes

  1. Everyone’s schedule and body are different but I have had almost no problem with morning BGs and dawn phenomenon in a long time. What seems to work for me is more related to sleep and stress in general rather than my Lantus injections (I use MDIs, not a pump).

    I am lucky in that my job is usually late morning or later, so I never have to get up with an alarm. I wake up naturally every day, whenever my body is ready. And I don’t sleep in on weekends. So seven days a week I am up between 7:30~9:00, naturally and generally well-rested.

    Plus I try to avoid screens before bed – computer and phone and TV. I’ll read my blue light-less Kindle or a book or nothing.

    All of that seems to make my pre- and post-breakfast BGs behave very well. I used to try to fix these problems with different insulin approaches but being calm, unstressed, and well-rested is what really made the difference.

    1. I agree with you. I’m up for work quite early, so I do find it is more of an effort for me to switch off and go to bed early in order to wake up well rested/less stressed.

  2. Ohhh dawn phenomenon! How badly it can screw everything up. Its good when you get it though. I havent had to change my night & morning rates to account for any changes in over a year now, I’m on a streak! But it does rely heavily on going to bed with good BGLs.

    I had a giggle when you said 9am is not a sleep in for you. I get up at 6am every day, whether I want to or not (damn body clock!). 7 am is definitely a sleep in for me. I wish I could sleep in until 9am. But when I think of my uni student days 9am was normal and 11am was a sleep in. Its funny how things change & how normal hours differ for everyone. I have to start my higher basal rate at 3am to account for wake up hormones at 6am.

    1. I think routine is key to consistency in basal rates….mine has been a little erratic lately, cue lots of changes. And 9am is definitely a very late sleep in for me…I can’t stand the thought of sleeping through the day!

  3. Hi Frank
    I noticed that your basal rates vary significantly on the display on your pump – by as much as 400% from 8 am to 4.30am, and that in your blog you talk about changing your basal rates the night before you go to work. Did you do fasting tests to determine to determine your basal rates when your pump was set up?

    1. Hi Michael, so first I did a basal test for my evening window 12am-6am. Once that was right, I did a basal test for the morning window 6am-12pm. The higher basal rate at 4.30am is to cover dawn phenomenon when I wake up. The rates then gradually go down at 7 and 8am when I start working and doing physical activity, and my insulin is more sensitive. Does that answer your question?

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