Why I measured my blood glucose continuously for 2 weeks, and why you should, too.


I’ve been meaning to write this blogpost for almost two months, and it’s finally here! So, in mid June I wore the above cyborg-like gadget on my upper arm for two weeks. No, I haven’t quite become *that* kind of biohacker, starting the possibly inevitable merge of human flesh with technology. Instead, I was measuring my glucose  with a Freestyle Libre continuous glucose monitor!

Why would a fit healthy person like me want to monitor my blood glucose? Well the main reasons are out of interest; how do certain foods affect my glucose? While the GI of foods can be a helpful gauge as to how certain foods spike blood sugar, it doesn’t tell you how foods in certain combinations affect blood sugar, or how they affect individuals (and there is definitely variation, which depends on factors such as genetics, stress level, sleep, activity, etc). Secondly, the “healthy range” glucose that your doctor might be okay with and what is considered “normal”, is in fact not aligned with the range for optimal health and longevity. This article by Chris Kresser is an excellent explanation of why “normal” blood sugar isn’t normal. Lastly, a lot of so-called healthy people are running around with abnormal spikes in blood sugar, as shown in studies like this,where the senior author, professor Michael Snyder ” encourages everyone—including those who think of themselves as healthy—to check their  sugar with continuous glucose monitoring about once a year”. (Excitingly, he also talks about environmental factors including the microbiome affecting how people process sugar, saying “I think understanding the microbiome and manipulating it is going to be a big part of this, and that’s where our research is headed next.”)

So in this vein, I got myself a Continuous blood glucose monitor (not the first one either, this was number 3 I think). I am interested in optimal health, not merely “adequate according to current societal standards” health. I reject the view that Alzheimers disease, cancer, and arthritis are inevitable for all people as we age, or that they can’t be prevented or at least delayed. Therefore, it was important to me to track my sugars, and ensure that my general diet results in optimal blood sugars.

So what are the key insights I learned from my two week tracking?

  • My day 1 sugars were pretty much the lowest, with my sugars being between 2.6mmol/l (46.8 mg/dL) and 5.9 mmol/l (106 mg/dL)The “red zone” is anything below about 3.9mmol/l). I ate fairly low carb including my regular bulletproof coffee,  though in the evening I did eat a HUGE piece of my low-ish carb blackforest cakeScreenshot_20180802-201945
  • When I ate paleo-ish whole unprocessed carbs with plenty of fat (my usual way of consuming carbs), my BMs did go a little higher, but still never higher than about 7 (which was admittedly when I overindulged in sweet potatoes.
  • There were a couple of days when my sugars were a bit more erratic such as on the 22nd June. You can see the spike, going to about 7.7 mmol at around 3pm, which was an hour after I ate a bunch of sweet potato and paleo ‘cake” which had arrowroot flour. A good reminder that even grain-free, sugar-free treats are still treats, and over-eating even healthy foods, is not that great for you.Screenshot_20180802-202157
  • My estimated Hba1c is 4.8% which is in the range thought best of optimize longevity.hb1c-211729


So there you have it; I learned a lot about how my body handles various foods and food combinations. I can’t wait till more companies make CGMS and the price comes down (my freestyle cost just over £50 so not super cheap, but still worth it for the information one can glean, and is super user friendly). I think I will be a bit more scientific next time I track my sugars, and do Robb Wolf’s seven day carb test  next which will allow me to really zone in on *which* carb sources are best for me.

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