My CGM Experiment

Dr. Avi Charlton trying a CGM experiment on herself.

My CGM experiment

I got a Continuous Glucose Meter (CGM) for fun. It costed me $99 including postage. I went to the Freestyle Libre website. I did say I am a diabetic. 

I waited a week or 2 for life to settle down and I have time to write a blog.

Day 1 - Sunday 23 Oct 2022

CGM data from around 9AM to 12AM.I woke up, keen to start this experiment. 

7:15am – put on CGM, takes 1 hour to start working

8:15am – took off to go for my usual run. Its meant to be 15km. I run fasted.

I scanned the CGM, 15 mins and 30 mins into the run. It spiked to up to 14 at 1 hour!! I didn’t expect it to spike that high. But this is normal response to exercise. Your body is mobilising glucose from my liver to supply muscles and increased circulation. Then again, someone else suggested maybe the machine isn’t very accurate in the first 12 hours. I will try again next time I run on Wednesday.

12 noon first meal – 3 egg omelette with avocado, mozzarella cheese crust. No spike. blood glucose stayed around 6.8.

5pm – I sneaked in a few squares of Vitawerx white chocolate and a few almonds. A little spike in blood sugar. Went up to 7.5 after 20 minutes of this little snack.

6pm – dinner with beef brisket, corn, sweet potatoes, cauliflower and broccoli cheese bake. I do allow myself some carbs after running. No spike after.

The plan for the next day is to stay low carb all day. The day after I might experiment with some higher carb foods.

Day 2 - Monday 22 Oct 2022

CGM data from 9PM to around 8:30PM. Time in Target reads: 100%. Last Scan reads: 7.1mmol/L. Average reads: 5.6 mmol/L.

Mondays are rest days from exercise, cos I did a long run yesterday. I haven’t been very active.

I wake at 6am, start with an electrolyte drink. I got a sample from Keto Weekend, this is Privet. Glucose 7.3

8am- breakfast is 3 eggs and avocado (sadly ran out of mozzarella cheese). Glucose 6.1

9am – glucose 6.3

I go to work to do a normal GP day.

12 noon is lunch time. Glucose 5.7 before lunch. Beef briskets leftovers from last night, cauliflower and broccoli with cheese

2:48pm – glucose spiked at most to 6.6

6:45pm dinner. Glucose before dinner 5.6. Dinner was chicken wings, cauliflower, asparagus, carrots. I did have yoghurt and blueberries for dessert, only a tablespoon.

8:30pm – spiked to 7.1

Plan for tomorrow is …. Try porridge for breakfast. I have some duck with a orange sweet sauce for lunch with more briskets. Meatballs and spaghetti for dinner!!

Day 3 - Tuesday 23 Oct 2022

Cup of rolled oats with blueberries and two strawberries.
2 slices of toast on plate next to a plastic container filled with cooked duck in orange sauce.
Cashews in plastic bowl.
Red sauced meatballs with pasta on plate.

CGM data from around 7:30PM to around 8PM with arrows showing what was eaten at the time of certain spikes in the readings.Tuesdays are strength days. Barbell squats, dead lifts, ball slams. I actually missed the last 2 Tuesdays, just cos too busy. Great to be back doing strength work. I always workout fasted. LMNT electrolytes after coffee. (Black with 1 tsp cream). Exercise spiked my glucose to 10.4.

The plan for CGM experiment is – CARBS!!!! Low carbers, please don’t try this at home!!!

After my workout, I had a tub of instant rolled oats. Just add water!!! I also added blueberries and a strawberry. It tasted good, cos got honey in it!!! After 1 hour, my glucose went up to 9.4!!!! OMG!!!

I worked the morning busy in the clinic. I was hungry by 9:30!!! I never get hungry if I eat 3 eggs. 

I was starving by 11:30 and ate my lunch cos a patient came in late. I had some leftover duck in orange sauce and added 2 slices of toast, just to add more carbs!!!! After 1 hour sugar went up to 11.1!!!! I, now, think, I might have diabetes!!!! It was still up to 8.3 , 3 hours later!!!!

Again, hungry at home, ate a handful (or 2 ) of cashew nuts around 5pm. 

At 6:45, I had speghetti and meat balls. It was a ‘small serve’. 1 hour later, whilst typing this, its up to 8.1. 

OMG!!! Please don’t try this unless under medical guidance!!!! 

Plan for tomorrow is back to low carb for the next 2 days. I need my brain power the next 2 days!!!

Day 4 - 26 Oct 2022

Peanut butter, yoghurt, blueberries, strawberries, and cacao nibs in small bowl.
Beef brisket, 3 avocadoes, broccoli, cauliflower, and cheese on plate.
Atkins low sugar chocolate bar.
Crumbed fish with asparaguses, carrots, and broccoli on dinner plate.

CGM reading with an arrow labelled Run pointing to the massive spike in the reading.I am staying low carb today cos I am working in my low carb clinic. I need super brain power to help these patients!! Wednesday is a run day. So woke at 5am. (Meant to be 5:30, but the husband decided to wake earlier than I want and I couldn’t keep sleeping!!!)

I went for a run, around 5.5km just near my house. It was drizzly rain. Rain doesn’t bother me. I was drenched at parkrun on Saturday. Just need a shower after. 

LMNT didn’t bother the blood sugar. Running did spike the sugar again up to 11. 

I ate yoghurt, berries, peanut butter and cacao nibs for breakfast. Unfortunately, didn’t have much time to keep checking sugars this morning as I was busy at work. 

I put up a post on Facebook to see what foods people suggest I try. There are so many suggestions!!! I may not be able to try them all. But a lovely lady called Carol noted this and brought in a bag of goodies including oats, sweet yoghurt, muslin bars.

Lunch was leftover beef brisket with cheese broccoli and cauliflower and avocado. No spike in sugar.

Mid afternoon , I tried an Atkin’s bar, milk chocolate mint crisp. With the terrible ingredients, it actually didn’t spike sugar.

Dinner was crumbed fish with veggies and butter. I had a 1/3 bar of Well Naturally dark chocolate. That was ok for my sugars too. 

So today, my sugar stayed pretty well in range the whole day. I felt pretty good with good energy. Also had some good results from my Low Carb Clinic. Plan for tomorrow is stay low carb. Again, I need to have brain power for hosting the free info night at my clinic!!!


It was overall a great experience for me. I wanted to experience what it’s like from the process of ordering to delivery to wearing the CGM. 

I found out how food affects blood glucose closely. Eating carbs, for example porridge and bread significantly caused a rise and blood glucose which persists for a few hours. 

Staying low carb maintained a flat line. 

Exercise made a spike but I have learnt that is physiological and a normal response. 

I would highly recommend anyone who is keen to learn to get a CGM for self learning. It was such an interesting experience.

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