Tracking my blood glucose over a month with a sensor stapled to my arm

Aaron Ng
Aaron's Blog
Published in
3 min readJan 17, 2017


Note: This post is backdated to the date of the experiment for posterity. I’d originally planned a more extensive post with interactive data but had to deprioritize it because of time constraints. :(

Between December 2016 and January 2017 I wore a wireless blood glucose monitor in the back of my arm. The sensor is the UK version of the FreeStyle Libre which is made for diabetics to monitor their blood glucose levels. It comes as a sensor that staples to the back of your arm, with a reader for reading your levels throughout the day. I’m not diabetic, but I’m interested in quantified self and deriving insights from normally invisible things happening inside of our bodies.

So why did I do this?:

  1. A more transparent view of what’s happening inside my body is empowering and informative.
  2. It’s a small peek into the future. We’ll all have common devices that give us all of this data one day.
  3. Blood glucose levels mark all sorts of interesting states like diabetes risk and atherosclerosis, to energy levels and alertness.
  4. I wanted to debug an issue where I’d occasionally be crippled by sleepiness, dizziness, and headaches after lunch. I suspected this was due to reactive hypoglycemia, so I was looking out to find low blood sugar levels correlated to a certain subjective state.
  5. I also made a small app called Tracker (see more about Tracker here) to log my subjective energy levels every hour during this experiment with the hope of cross-examining the data to debug #4, and also just to see if there was anything interesting.


  1. It’s incredible to see your body to react to the things you do– something like drinking a 7UP and watching your blood sugar double in real time is really sobering. It’s a natural healthy response, but it’s one that’s normally completely invisible to you. It allows you to build a more complete image of your body.
  2. These devices still aren’t perfect, but they represent really amazing state-of-the-art consumer devices. They’re wireless, waterproof, and last two weeks on your arm without needing to charge. All you have to do is hold up your reader to see your blood sugar levels– it’s a small flash of the future.
  3. Today, these devices allow you to tie your actions to a result in your body– tomorrow these devices are going to know what your patterns look like automatically and use that to keep you healthier.
  4. Some regulations are kind of annoying– the reason I had to use the UK version of the Libre is because the US version doesn’t allow patients to access their own data. It has to be unlocked by their physicians. This, to me is a major barrier to all kinds of innovation in citizen science, medicine, and more.

And what about your possible reactive hypoglycemia?

I was expecting to find a strong correlation between my crippling tiredness after meals (marked as Awful on the app) and lower blood glucose levels. I didn’t. While I noticed the ‘crippling tiredness’ often, I did have difficulty trying to control enough variables to consistently replicate it. It could still be reactive hypoglycemia, or it could be low blood pressure, or any number of other things. I’d like to be more strict and attempt the experiment again. Subjectively, intermittent fasting has (subjectively) helped a lot. I feel much better and more mentally alert throughout the day.

Those are some takeaways from my month long experiment. I’d gladly do it again– and highly recommend anyone interested in biohacking, quantified self, or just ~the future~ to try it out. You never know what you’ll find from a more transparent view of your body.

Let’s talk about biohacking and quantified self on Twitter or Instagram.



Aaron Ng
Aaron's Blog

technology, meditation, aesthetics. i’ve done work for companies including Facebook, Square, and Apple.