This April I wore a continuous blood glucose monitor (CGM) and tracked everything I ate for a month. It was an experiment in metabolic health and my gateway into the biohacking world. The results were surprising despite what I thought was my relatively healthy diet. Here are five simple steps I took to get started.
1- Order a CGM
CGM's are usually small sticky skin patches with a tiny needle in the middle. Most people wear them on their upper arm. I bought the Libre Freestyle by Abbott, which cost me £50 (~$68) each. One patch lasted 2 weeks, and each one comes with an applicator. It honestly isn't painful.
Most CGM's sync with a free smartphone app - all you have to do is to remember to hover your phone over the sensor at least once every 8 hours. Magical.
2 - Decide what you're going to experiment on.
The blood sugar readings are only the start. You need to have some input variables to compare that data to, and it helps to know what you're trying to test. I decided to eat normally for the first half, then tailor my diet based on what I'd learned to reduce blood sugar spikes in the second half.
3 - Track your food intake.
I used a simple google-sheets based form to capture what I ate and when I ate it. If you can't be bothered, a photo journal of everything you eat probably works as well. If you're using the Libre, you can alternatively do this within the app itself - which makes it very obvious what are the big blood sugar-spiking culprits.
4 - Take notes on your sleep, stress, exercise, and other lifestyle factors.
The big unlock for me was realizing that things like my stress levels, exercise, caffeine, the amount and quality of sleep I got, all affected my response to the same foods.
For example, poor sleep or high stress seemed to cause sharper glucose spikes with very similar foods. Walking after a meal (predictably) lowered my blood sugar much quicker, whilst interestingly resistance exercise sometimes put up my sugars. I also found out that whilst I felt fine with higher blood sugars, the "roller coaster" down below my baseline was what drove my cravings and made me feel awful.
5 - Reflect and adapt.
I did this exercise with my girlfriend and I was really surprised with some of the things that came out. Certain things like the type of oats (steel cut versus pinhead), or the sequence of food (peanut butter then oats or oats then peanut butter) dramatically changed the blood sugar curves for the same calories of food. We also had different responses to the exact same foods.
There's really no better way to get real-time data on your metabolism. This experiment positively changed my life and led me to try the ketogenic diet for the last 6 months.