Technology is growing every day, we are starting to see so many fitness tracking devices, even ones that track your sleep too. And these are actually really great tools to help you realize how much activity you’re doing each day, as well as the quality of your sleep.
I’ve started to experiment with pretty new technology called continuous glucose monitoring (CGM). Recently I did an experiment with it for two weeks, actually it was my second time trying this. I learned a lot, some confirmations of what I thought I already knew as well as some things that really surprised me too. I’d like to share my experience with you, maybe you’d then like to try it yourself, or maybe you would just like to try giving more attention to things like your eating habits and your meal timing.
Here are some of the things that I found.
As you would expect, the timing of high carbohydrate meals is especially important. For example, if I was doing a workout and I then consumed carbs with a combination of protein I did not see too much of a spike in my blood sugar. Even if it did spike, it came back down again very quickly. However, if I consumed carbohydrates without doing any workout then I saw a more intense spike and it lasted for a much longer period — which of course then leads to fatigue and to feeling hungry again very quickly.
Carbohydrate sources: Surprisingly I responded very well to sweet potatoes and to white potatoes. But I ate chestnuts as a snack which caused a rapid spike in my blood sugar. On the other hand, a rice based organic cereal with homemade almond milk did not affect my blood glucose levels at all. So the quality of your foods certainly makes a big difference too. Interestingly, homemade sourdough bread, made with ancient grains or organic flour, did not affect me very much. But putting honey on it did increase my blood sugar a little too much. In addition, I found that fruits has a big effect on my blood glucose too.
I should point out that of course during the day our blood sugar increases and decreases due to many factors, including stress, exercise, and food. And that is completely normal. However, It’s important to understand which food sources and which combinations in a meal cause which reactions. A quick spike in blood sugar levels that comes back down very quickly has a very different effect on us that an increase that remains high for a longer period.
Sleep: I normally eat my dinner early, but for this experiment I tried some early dinners and some late dinners, plus a combination of small healthy snacks after dinner. I found that I slept very well no matter what I did, but when eating later or when snacking before bed my blood sugar levels would spike after 4 to 5 hours sleep. The spike went up to a range of 128 to 147 (7.1 to 8.1) which is extremely high for me. I didn’t feel anything, but I am sure that if were to track my sleep at the same time I probably would see that my REM sleep cycle was disturbed.
Very high protein meals: My diet is generally very high in protein, I normally eat 40 to 50 grams of protein in one meal, which is around 7 to 8 ounces of meat. I did see a small spike in my blood sugar with high protein meals, but when I combined protein with fat I did not see any spike at all. Combining protein with carbs, however, caused a very rapid and high spike even though of course I chose healthy carbs sources.
Supplements: Coffee, BCAA (branch chain amino acids) and pre-workout supplements, which contain small amounts of caffeine and natural sweeteners, did not have any effect on me. I’ll explain why in just a moment… Whey protein did cause my blood sugar to rise, however whey protein isolate, which is slower to digest, had no effect.
Exercise: Different types of exercise of course cause very different responses. For example, an easy walk will have a very different effect than high intensity exercise such as running or weight training. Of course, it was not a surprise that low intensity exercise will lower blood glucose levels while high intensity exercises will increase them. However, it doesn’t mean we should not do high intensity exercise, as you will see some very positive after effects of high intensity training, such as being able to consume a high carbohydrate meal without seeing a big spike on your blood sugar.
Fasting: I saved the best one for last! I normally practice 24 to 48 hour fasting fairly regularly. However, I do keep my training routine during my fasting too. So I will normally consume coffee, no-calorie BCAA, and pre-workout supplements to keep my energy high for my workouts. During my CGM experiment I did one 48 hour fast during which I drank black coffee with a little natural no-calorie sweetener. I also took BCAA and my pre-workout just before my training. And guess what happened — whereas in my normal fed state these did not have an effect on my blood glucose, during my fasted state they did, so I started feeling low energy and tired during my fast.
A few days later I decided to do a second fast, this time for 72 hours with only naturally sweetened electrolytes, nothing else. I did a workout on all three days, with two days of strength training and one day slow jog. I felt amazing with no hunger, no energy drop, no sleep disturbance, and no headaches. So without any stimulants I saw the best results. My blood sugar was very stable all day and all night throughout the full 72 hours. That actually made me happy to see that during longer term fasting I could still keep my energy levels high.
- If you are not doing activity then don’t start your day with a high-carb meal.
- Eat your high carb meal after your high intensity training.
- Choose high quality carbs such as sweet potatoes, organic rice based cereals, homemade granola, or sourdough bread.
- Consume protein together with fat.
- If you are using protein powder then choose isolate.
- Stop eating, including snacks, at least 2 to 3 hours before bed.
- If you’re like me and you love fruit then make sure to eat fruit on its own.
- After low intensity activities try to not eat too much.
- If you want to fast then cut out all the stimulants and consume only electrolytes, such as magnesium, potassium and sodium.
Of course I want to remind you again that these are just my own experiences so it does not mean that your body will respond in exactly the same way.
Here’s what I used during my experiment (I don’t have any connection or financial interest with any of these companies, they’re simply the ones that I chose):
- CGM from NutriSense https://www.nutrisense.io/
- “Snake Juice” electrolytes, available on Amazon
- BCAA and whey protein from ATP labs https://atplab.com/
- Pre-workout and whey protein isolate from HD https://hdmuscle.com/
- Organic coffee by Kicking Horse https://www.kickinghorsecoffee.com/en
I hope that this information helps you and maybe motivates you to try out some experiments and changes in your life!