3 Most Surprising Lessons from my continuous blood glucose monitor

lentils & hummus

It’s been over 4 years since I was diagnosed with gestational diabetes.

So I’m comfortable with managing my blood sugar by eating low carb.

But as a girl with 2 science degrees, I do love a good experiment.

And am always looking for ways to improve.

So for the last 2 weeks I’ve been using a continuous blood glucose monitor to track my sugars 24/7.

Super fun!

Here’s what surprised me this time.

3 surprising lessons from my continuous blood glucose monitor.

1. What you eat during the day impacts night blood sugar.

I hadn’t noticed this before but the biggest surprise this time wasn’t my results during the the day.

It was the spikes some food caused when I was asleep. Especially around midnight.

The most alarming of these was after Fergal’s birthday cake.

I had thought things weren’t too bad during the day.

But when I woke up to my highest spike ever (see below). I decided there won’t be any more butter cream frosting for me.

Glucose graphs

Easy decision.

2. Lentils are OK!

My prime motivation for testing this time was to see the actual impact of lentils because I’m keen to reintroduce them.

My first test – a delicious Spiced Lentil Soup with Tahini Yoghurt seemed fine at the time, but gave another middle of the night shock (see below).

Glucose graphs

But I wasn’t giving up that easily. What if I reduced the quantity?

So I re-tested with a Sausage & Lentilotto (like risotto made with red lentils). With a small serving of lentils (100g / 3.5oz) and the sausages it was smooth sailing (see below). All night.

Glucose graphs

Bring on the lentils!

In modest servings of course ;)

3. Spitting out doesn’t work.

I’m a bit ashamed about sharing this one.

But ever since my days of being a wine maker, and learning how to spit out when tasting, I’ve had this bad habit of eating and spitting things out.

Remember that graph above from the Birthday cake? That was even with me spitting out the frosting.

An excellent motivator to stop. Knowledge really is power.

What do you think?

Is it helpful when I share about my diabetes journey? Would you like to see a followup of the other things I tested? Let me know in the comments below.

And have fun in the kitchen!

With love
Jules x

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  • My son-in-law and grandson are Type 1 diabetic so learning ways to cook for them is always appreciated!

  • As one who is back to being borderline diabetic (A1c = 5.9), apparently most likely due to all the stress we’ve been through in the last few months, I am very interested to know what your tests turn up. I would also like to be able to re-introduce beans and lentils into my diet, so again your experiments are helpful. I am rarely tempted to try anything like birthday cake (we missed my having to eat some of my own by being thrown off our cruise ship very early), but I did have to eat our table mates’ anniversary cake. Which makes me wonder how long the effects of birthday cake spikes last? I would tend to guess that any such spike would contribute to A1c levels.

    • Hi Susan

      It took about 36 hours to get back to normal after the cake. If it’s a one-off event in the 3 months the A1C is looking at I don’t think it would have a siginificant impact – BUT if it was every week, that would be a different story.

      The lentil experiment was really fun – I am going to include them again but only once a week or so and in small quantities.

  • I am also diabetic, on insulin, and suspect I might have spikes during the night

    . I am interested in your personal experiences with certain foods, but woud also like to know about the continuous blood sugar monitor.

  • I too am very interested in your experiments. I appreciate the lentil tests as it answered my question about smaller portions and has added to my menu options. Thanks for sharing.

  • I’m not diabetic but I know very little about it so, very interested in further experiments!
    & If you can devise any experiments that help with implement lentils to my pulse-resistant husband, please let me know! = )

  • This is a kind information.
    What all i experienced, if we reduce the belly fat, almost your mitochondria starts working again. And it is helpful to reduce the spikes, greater he belly fat, higher spikes in BS. Moreover exercise is key to make dowm BS even while sleeping. Also dawn phenomenon gets activated in night, so better not to check BS during 3 am till 6 am. Cutting long into short, one of my doctor friend was saying perfectly, he said, what you eat, you need to observe it.. thats all.
    My journey is from HBAIC 10.2 to 5.9. Then after 1 year, it became 6.7 again it comeback to 6.2.. all the the time we have to be calm and stressless. One good and big news is fractyl has discovered the treatment of T2D, for more information type on google fractyl new and check the 30th march news. Trust men it is break through in T2DZ HISTORY

    • Normally 3 am or in the middle of the night blood sugar spikes is due to the so called Dawn phenomenon. As you are eating less during the evening or night, you tend to starved yourself, hence the body in its effort to avoid hypoglycemia during sleep, it releases your spared glucose from your muscles and liver into the blood stream. This resulted in getting high fasting blood sugar reading early in the morning. Nevertheless, food factors must be part of its causes. Perfectly said, ” What you eat, you need to observe it”.

  • Great article. in January my HBA1C was 10.9 and decided to change my diet. In morning 3 full eggs with 100g of vegetables, afternoon 150g chicken and 250 g of vegetables and for dinner 150g of chicken/paneer/tofu with 259 g vegetables. Within a week if starting my BS dropped and had to stop taking my medicine. Although I do test my BS, 2 hours after every meal. It’s been over six months and still without medicine and my morning sugar is around 90 and 2 hours after meal is 120. Glad to find this article as I have been on same diet for 6 months and would love to try new recipes.

  • You have orthorexia, please see a doctor, living in your head must be absolutely miserable. FYI, alcohol causes 7 types of cancer. I don’t think lentils are what you need to worry about.

    • That was really interesting. I’d love to see more studies with the Libre. I dont understand how spitting out frosting can have that much of a spike. Is the sugar absorbed into the blood that quickly?? Is everything—could you get the benefits of some vitamins by spitting out vegetables? (Not that I’d do that but interesting from a science-y view)

  • Hi Jules, it is nice reading your posting and experience. I am diagnosed pre-diabetic. I don’t know how to cook but try to reduce carb diet. Looking forward to read more updates.
    Thank you. Isaac

  • I am always interested in learning more ….. when I asked my doctor about the number going up while I was sleeping I was told it was not affected by what I ate that day …. yet I experienced the same as you. If I kept my carbs low and did not snack just before bed ( i was also advised to have have a bedtime snack which I very soon gave up after realizing it could be making my sugar spike whike I slept) the low carbs helped greatly ! So yes yes yes ….. limit those carbs???

  • Glad to see something positive. I’m type 2 hba down from 68 to 39 but hard work getting there and I’d like to hear more about what I can eat rather than what I can’t eat.

    • Good for you Mac!
      I think focusing on what I can eat really makes a big difference for me too.
      There are so many delicious low carb foods to enjoy – I don’t ever feel deprived :)

  • I manage my diabetes well by not eating any food again from 7 o’clock in the night and in the morning I eat normal and same in afternoon I reduce my food,I tried it over 3 months now,today 2 of my medication was struck off hurray.

  • I am glad I saw your article Jules. I am pre-diabetic and I need to lower my A1C. This is very scary to me. I need to act fast before I become a diabetic. Your article and the questions people have are so informative and helpful. Keep up the good work.

    • Give up Bread, Give up all Sugars,
      No Tortillas, No Flour.
      Munch on Vegetables – Broccoli,
      Green Beans, etc.
      No Buns, No Fries, No Potatoes.
      Exercise – do twists while watching TV, march in place, grab 20 lb weights, lift often.
      No Fruits till you drop weight, Numbers – move, exercise

      • Hey Greg

        I disagree with the need to ‘give up’ anything – for me it’s all about removing the desire for bread, sugar, tortillas, flour. When I understand the damage they do to my body I don’t want them.

  • Very interesting. Please keep posting experiments with different foods.
    I am also using CGM out of curiosity.

  • Thanks for these insights. A lot of our food in this part of the world is carb based. Staying strict on no or low carbs recipes is really not easy but with discipline we are coping. At the end it’s a marathon and not a sprint.

    • Yes it’s a marathon Egemba!

      I find focusing on what I can and want to eat really helpful. There are so many delicious low carb foods available. I never feel like I’m missing out – especially whan I know the damage that high carb choices are making.

      You can do it!

  • good article….3 weeks ago with no warning l was diagnosed type 2….since then I have went strict low carb and my fasting bs is just a shade over 100 most mornings.the nightime spikes are hard to explain a doctor told me.metformin works during the night better than the day doses lve read. maybe we spike in our sleep because theres no activity? i know I try to fast from 4pm until 5 am to lower night time blood sugars.

    • Good for you Mark – low carb is amazing for getting results.

      I don’t have any knowledge about metformin – but night time spikes have something to do with cortisol I believe.

      Keep up the great work!

  • Thank you for sharing this! I greatly reduced my alcohol intake over the past few years and noticed that any time I have alcohol now, I have a weird spike in heart rate in the middle of the night. Sometimes it wakes me up and I can’t get back to sleep. I definitely suspected the sugar in the alcohol but have always been surprised that it happens even with 1 glass of wine. I’ve had this happen with too many carbs, too! So weird.
    Fortunately/unfortunately, I can’t even drink any more because we were in a car wreck in March and even a glass of wine leaves me with serious brain inflammation and a hangover that lasts multiple days. Definitely makes it easier to give up!

    • Talk to a doctor about your symptoms. I’m type 2 and had what I thought was severe heartburn during the night- it would wake me up. About 5 months after this started I had a major heart attack, the kind that’s called a widowmaker. I got treatment fast, then started low carb with intermittent fasting – basically eating 1.5 meals per day of low carb. My hga1c went from 12 to 6 in 3 or 4 months.
      Always looking for more recipes, and I find your experiment very interesting.

    • I have had a similar experience with alcohol Catherine – I actually don’t desire it any more which is incredibly strange for me given I used to be a wine maker!

      There are lots of benefits from avoiding alcohol. :)

  • I was diagnosed with gestation diabetes so from then i decided to eat health and reduce my weight to avoid type 2 diabetes..I sometimes monitor my blood sugar morning and during the day but would love to monitor it during my sleep what did you use yours to monitor during your sleep tia?

  • I have been diagnosed with GD and the Libre really helped me see how to control my sugar levels and how exercise etc helped keep them level. I’m curious if you went from GD into type 2 diabetes? Or did the GD diagnosis just really help you learn the healthy balanced way of eating?

  • I have been on a low carb diet so to speak for the last eighteen months now, during that time I have indeed lost weight to the tune of 35 kilograms , I walk about 6 to 7 klm five days a week , my A1C up until recent times was marginal , last blood test was up , we knew we would eventually have to go back on insulin, the problem is my liver producers glucose, to feed the vital organs whilst asleep , the result being high morning readings…..

  • You thought the birthday cake gave you a spike… Wait ’till you see commercial pizza with its high fructose corn syrup infused sauce!

  • I have been a type 2 diabetic for 20 years. I am on insulin now and I have the Libre sensor on my arm and I have learned a lot. I am on a low carb diet, no sodas, no bread, no chips, no fried foods. I eat a lot of veggies, salads, a lot of high protein foods grilled chicken and fish. A lot has to do with how much you eat. If we fall off the wagon get up shake it off, and start over.
    Don’t give up?

    • Definitely don’t give up Tina! And I agree the amount you eat has a massive impact. I had a very small portion of home made ravioli with my almond pasta and it was fine. I enjoyed it but didn’t need any more. There are always options :)

  • Hi !!! Loved your graphs .
    I have thought a lot about spitting chocolate , cake etc .
    Love your honesty !!!

  • It would be a real help to hear about your journey with looking after your blood sugar with your recipes and what works.

  • It is so helpful to read of your diabetes journey. Really appreciate your sharing this and all its meal planning implications

  • I am pre type 2 monitoring 3-5 times and have also noticed late evening spike. My body is slow to process food is my guess so have to watch day time eating.

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