How To Lower Your Blood Glucose With A Continuous Glucose Monitor

Justin Lawler
Sep 8, 2017 · 6 min read

Diabetes and pre-diabetes is a big problem worldwide.

It’s the way we’re living that’s causing diabetes. We overeat on processed food. We don’t exercise enough. We’re too sedentary.

Over the last three months, I’ve been using a continuous glucose monitor, and have used it to guide small lifestyle and diet changes in an experiment to improve my glucose levels.

Big thanks to Mark Hyman and Jason Fung who’s work on improving insulin sensitivity and even recover from diabetes inspired me to do this work.

The Glucose Monitor

The two main glucose monitors on the market now are the Freestyle Libre from Abbot Labs, and the Dexcom.

I’ve been using a Freestyle Libre monitor from Abbot Labs (initial impressions here).

Note — this is available without prescription in Ireland, but in many other countries you will need a prescription.

Glucose, Diabetes and the Continuous Glucose Monitor

Diabetes is a problem with Insulin sensitivity. When diabetics consume glucose, the blood sugar goes up too high, and it stays up for too long.

Pre-diabetes is seen as fasting glucose levels above 100. Diabetes is above 125.

With a continuous glucose monitor, we can see our glucose every moment in the day. What spikes it and what brings it down.

What gets measured, gets managed.— Peter Drucker

With the real time glucose feedback, we learn what causes the spikes. We also we learn what reduces them, and from that, we can work on reducing daily average glucose.

What’s Worked for Me

1. Low Carb — Nothing works better than reducing the glycemic load of in my diet.

Eating protein or high fats actually, reduces blood sugar levels after eating. Digestion takes energy.

Over the last month I’ve been trying zero carb breakfasts, so my first time my glucose goes up is at lunch time.

2. Movement after meals — even low-intensity exercise like walking will blunt the glucose spike post meals, from over 180 to 140.

Standing desks are great. Fitness trackers help also. Most have a ‘sedentary alert’ on them, to nudge us when we’re sitting for too long.

There’s a lot of science and clinical studies on this.

3. Portion Size — I’ve had some biggest spikes have been when I have rice in Asian restaurants (over 220). The portion of rice they serve is enormous!

I’m getting used to asking for half-portions now.

4. High-Intensity Interval Training — I’ve had some of my best glucose days when I did short interval sprints in the morning, getting the heart rate up to close to my maximum. Again, spikes are much lower and levels stay up for much less time.

Note, the science behind this is well studied and known.

5. Sleeping Well — There’s much research out there linking lost sleep with glucose control. Two to three bad nights sleep can bring on pre-diabetic glucose control.

For me, the worst week of glucose control has been when travelling. While I’m missing sleep, there’s also stress, and bad food choices, of course, don’t help — so it’s hard to say for definite that it’s only sleeping.

It’s something I’ve been working on improving over the last three months, increasing sleep times and very likely has helped with overall control.

6. Reduce snacking — Only three meals a day. Or if I’m feeling hungry, low-carb options.

Glucose levels after a meal will take 2–3 hours to stabilise. After a snack, it could be 30–60 minutes, so snacking pushes up average glucose levels.

Dr Jason Fung has a great post on the ‘snack often’ theory.

7. Add more fibre — eating high-glycemic carbs on their own tend to hit my blood levels very quickly. Within 15–30 minutes even.

More fibre in a meal will reduce the overall spike. It reduces the overall glycemic load of the meal by slowing down the digestion.

The order of food seems to matter also. If I eat a salad first, and faster carbs later, it looks like fewer spikes than eating fast-carbs first.

Mark Hyman talks about this.

8. Hot and cold therapy — my glucose control gets much better after hot yoga or a sauna — high carb meals don’t spike my levels as much or for as long.

Rhonda Patrick talked about this at the biohackers conference Helsinki 2016.

What Didn’t Work

Intermittent fasting. It’s being talked about everywhere as the solution for insulin sensitivity.

For me, it didn’t work. I got starving by lunch, and I’d overeat, and glucose levels would go through the roof all afternoon, messing up my sleep.

My average glucose levels were higher with intermittent fasting than with three smaller meals a day.

Maybe this will work for others, but for me, it didn’t. At this stage. Maybe in the future when I’m more on top of my eating habits I’ll be able to do it.

Where Next?

Stress management — the highest spikes I’ve had so far has been when I’ve been stressed. Starting a new job (over 250) and giving a public speech (over 300).

If it’s just a once off (public speech), it’s manageable. But if it gets chronic, then getting a handle on my stress has got to be part of the overall approach.

Supplements — chromium, cinnamon, magnesium are all supposed to help. Much more listed here.

My Blood Sugar Levels — Before and After

Before, my levels weren’t good.

Lots of spikes over ten post meals. Overnight glucose high and unstable.

Comparing before and after:

  • Fasting glucose down 7%
  • Daily average down 12%
  • Spikes are lower — I used to spike over 180 regularly
  • Levels come down faster after meals
  • Low carb breakfasts actually lower glucose levels
  • Levels are higher at night — related to later meals and more carbs in my evening meals, to help with my sleep.

After three months I’ve improved my glucose control — achieved without major lifestyle changes.

Most importantly I’ve reversed my trend towards pre-diabetes (above 100). My fasting glucose levels are now 90, down from 97.


From my glucose figures, I was on a path to pre-diabetes.

Just having the basic awareness of my glucose levels has allowed me to make minor tweaks to my lifestyle to improve my levels.

Continuous glucose monitors will soon play a major part in our healthcare.

It won’t be long before glucose monitors are non-invasive. Soon after, fitness trackers will integrate the glucose sensors — fitness trackers are already working with continuous glucose monitors.

Soon after we’ll get intelligent apps using this data, to ‘nudge’ us to better health with contextual suggestions. They’ll catch pre-diabetes early. They’ll give us alternatives to medication.

Continuous Glucose Monitor Series (3 of 3)

Better Humans

Better Humans is a collection of the world's most…

Justin Lawler

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Self-Quantifier, tech-lover and biohacker. Organiser of Dublin Quantified Self. Developer. More at

Better Humans

Better Humans is a collection of the world's most trustworthy writing on human potential and self improvement by coaches, academics, and aggressive self-experimenters. Articles are based on deep personal experience, science, and research. No fluff, book reports, or listicles.

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