I have a lot of people, with and without diabetes, asking me whether it is normal that their blood glucose levels rise steeply (spike) after a meal? So let me explain in case you were wondering too.
The reason they know this is happening is because they’ve been using a wearable glucose monitor. If you see someone with a little white disc stuck to the back of their arm, they may well be wearing one of the more widely available ones. These discs last 2 weeks and show you what your blood glucose levels are doing 24/7.
These wearable glucose monitors have been around for a few years now. They were designed for people with diabetes who, up until then, had one choice and that was to prick their fingers numerous times a day to see how their blood glucose levels were doing.
Since last year, anyone with Type 1 Diabetes should be offered one of these monitors. They have been a revelation to many people and offer a safer and higher quality of life. It also means no more sore fingers. Type 2 Diabetes sufferers may also be offered these monitors, dependent on certain criteria. However, they can be purchased and some folk without diabetes have chosen to give one a spin.
You end up with a lot of data, including a graph showing you what has happened to your blood glucose levels across the day. And there are spikes! Eek!
Except that a rise in blood glucose levels is entirely normal soon after a meal, unless the meal is entirely carbohydrate free.
When we eat any form of carbohydrate, it is digested and broken down to glucose in our gut. This glucose is absorbed into our blood stream and, within roughly 2 hours, is taken back out of the blood stream by our cells who use it for energy or store it for later.
So, from the time the glucose hits our blood stream until the cells remove it, our blood glucose levels are inevitably raised (or spike, if you like). This is not something to be avoided at all costs, it is a physiological fact. And, unless you fancy living on protein and lettuce for the rest of your life, your body will happily be coping with this without your ever knowing anything about it (unless you wear a monitor of course!).
Now, my intention is not to belittle the enormous importance of monitoring and evaluating blood glucose levels for anyone with diabetes. It is simply to explain what our body does.
You may be surprised to hear that a person without diabetes might see a level of up to 11.0 an hour after eating. I saw it myself. I was given a monitor to trial when they were first launched and, after a curry and a beer, my levels rose to 10.6. It was a shock. I’m a dietitian, surely that can’t be!!!
What happens within 2 hours is what really counts. Within 2 hours, you would expect levels to drop back down to less than 7.8 if you don’t have diabetes. Fortunately, this is what happened to me. Phew!
So, my point is, if you use one of these monitors, whether you have diabetes or not, you will see your blood glucose levels rising over the hour (roughly) following a meal. You don’t have to achieve a flat line across the day. That is why we ask those with diabetes to focus on the 2 hour mark not the 1 hour mark. (Gestational Diabetes is a slightly different story – but let’s not get into that here.)
Does the size of the spike matter? Yes and No.
No. If you don’t have diabetes then the occasional very short-lived 11.0 will not harm you.
That said, if it is happening after the majority of meals and snacks, some tweaks to your food choices and activity levels would be handy, since it suggests that meals are not very balanced. Simple carbohydrates may be featuring heavily whilst vegetables and perhaps protein are cowering around the edges. But you don’t need to wear a glucose monitor to tell you that, a quick look at your plate will do.
Yes. For someone with diabetes, levels which run consistently and significantly high at this point are not great news. Blood glucose control across the day may well be less than optimal too. This is associated with damage to blood vessels and various bodily organs.
Here comes the boring bit….. As I said, I am a dietitian and you’d expect nothing less!
For most of us, a diet which comprises lots of veg, fruit, nuts and seeds, some lean protein (beans, lentils, chickpeas, tofu, fish and lean meat) and an elegant portion of carbs (preferably the wholegrain, high fibre variety) is going to provide all the nutrients we need. Couple that with regular exercise and our blood glucose levels will look after themselves, without the need to monitor and micro manage every fluctuation.
If you have diabetes, a balanced diet and lifestyle is a good place to start too and I can only imagine how useful it might be for many of you to finally have a 24/7 view of what your body is up to.