Firstly, I just want to make clear I do not see a healthy individual to gain any value from wearing one of these. Sure it's reasonably interesting, but I have not actually learned anything, apart from confirming what I suspected: these are not useful for healthy individuals. So save your money and read this instead.
They are very useful for people with diabetes or other conditions influencing their blood sugars like chronic steroid use for example.
But for me and other healthy people there is no benefit. I will explain why over this blog so you can save your money and time.
Blood glucose is a pointless measure to know
Your body is insanely complicated. I think we all know this and medics know this. We never know how individuals are going to respond to treatment because of the bodies complications and individual differences. Because of the complexity of the body measuring one thing in isolation and using this to determine whether a food is healthy or not is ridiculous. It would be like measuring a business solely on how much profit they made, when product sold, money reinvested, customer satisfaction are also highly relevant measures. Sure you can measure the business on just profit, but you'll likely get a wrong answer and hide the truth.
It's the same with blood glucose. I ate particular foods for a day purposely to not spike my glucose. Was this a healthy diet? NO! I ate bacon, butter, ham, eggs and 500g of nuts. Nothing wrong with these foods, but this is not a healthy diet if this is all you eat! There is a huge lack of fibre, which my bowels felt the effects from for several days, and it is extremely high in fat!
You could keep your blood sugar low while increasing your blood cholesterol, which can have much more serious consequences.
Below you can see my graph from another day. This is perfectly healthy and actually if you are active and doing regular sport I would argue is more healthy as it shows you have carbohydrate in your diet to fuel your exercise.
Blood glucose is influenced by so many things
Your blood glucose spike after eating may be a result of the content of your meal. However, you may respond differently to the same foods on different days.
For example, when you are exercising your muscles soak up all the sugar from your blood very effectively. This effect can last for as much as 3 days after exercising! This massively reduces your blood sugar spikes if you have exercised.
The opposite effect happens with some hormones. Cortisol is a stress hormone and is often released in the morning to help your body get out of bed. Cortisol also causes release of sugar into your blood. Therefore you may see a blood glucose spike first thing in the morning regardless of what you eat.
Adrenaline also causes a glucose to be released into your blood stream. Adrenaline is released when doing exercise and therefore you would expect to see a blood glucose spike if you are active regardless of what you have eaten.
These are just 3 examples. There are many more. Illness will spike your blood sugar, a high fat high fibre meal will reduce the spike from a meal and alcohol will reduce your blood sugar. This just shows blood glucose cannot be used as a measure of your health or the health of your diet.
One thing I have learned
Despite my blood sugars remaining in range (as expected because I don't have diabetes), I still felt hungry and still felt tired at times. This reminded me your body becomes hungry and tired regardless of nutrition, and sugar is not a quick fix for either of these.
This experience has also made me aware of what people who buy a moinitor may experience. I felt an urge to not eat carbs to keep my graph flat, even though I knew this was not a healthy diet. Once I ate carbs and saw I had a normal response I was calmer about this.
Applications for glucose monitors in sport
There may be some application in sport with otherwise healthy individuals.
To fuel for sport you need a lot of carbs to make certain your carb stores are full. This will spike you blood sugar levels. However, you do not want to do sport when your blood sugar is spiked as you want the sugar to be stored in your muscles. Also if you begin sport when your blood sugar is spiked you risk having a 'rebound hypo'. This is when your blood sugar rapidly fall when you exercise soon after eating because insulin is reducing your blood sugar and the exercise also reduces your blood sugar. Both these together can reduce your blood sugar too fast and cause a hypo.
Using these to see when you spike is over and your are ready to engage in physical activity is a small possible use.
Another possible use is in endurance sports to tell you when you need to be consuming nutrition to prevent 'bonking'. I have done a 2.5 hour cycle with mine on and my sugars were never in danger of dropping. I did still get tired however, showing me fatigue is caused by more than nutrition.
The use of continuous glucose monitors are banned in professional cycling. Chris Frome spoke out in argument of this decision as he felt warning of low sugar levels could prevent crashes.
When should you be concerned by a blood glucose spike after eating?
There is no reason to think glucose spikes are of any concern in healthy people.
However, if your glucose rises above 11 and does not come back down it's worth clarifying the result with a clinician. The monitors are only 20% accurate, so never get too concerned by the readings.
Also if your glucose levels are frequently dipping below 4, consider speaking to a clinician.
If you have found this blog useful or insightful please like, comment and share to show me.
Comments