If you want to know more about it you can just read about how diabetics treat different foods. Short version; high GI is fast high blood sugar, lots fat and sugar can results long period of with high blood sugars.
It is a CGM more or less what you would expect, insulin is the only hormone that lowers blood sugar, then you have all the stress hormones that raise it like adrenalin, growth hormone and cortisol plus glucagon for long time storage of sugars in the body. So measuring blood sugar with a CGM gives you a value between 2.9-13.5 mmol/liter that is supposed to give you picture of a rather complex system. A CGM also needs perfect access to your free flowing blood which in it self is a difficult task.
I'm more curious about the experience a non-diabetic person has. For one, the purpose of using the device is quite different, and not related to a life threatening situation. And because the focus isn't to manage this specific issue, the insights and potential utility seem like they'd be of an entirely different variety.
e.g. I know that the things I eat impact my blood sugar, but don't have the same kind of intimate awareness a diabetic person would have, nor would the changes in my levels have the same meaning/impact.
Put another way, and setting aside the issue of oversimplifying a complex system (so is measuring RHR, HRV, blood oxygen, etc.), the benefit of CGM for a diabetic person is obvious. The benefit of CGM for a curious person less so.
It is probably easier to find interesting things curious people with diabetes has done, sure you might want help to sort out the interesting bits.
Optimizing sugar in take for exercise might be an interesting thing todo as non diabetic. There is no tool to continuously measure ketons though which is the fun part. CGMs are so slow. I really see no use at the moment.
I'm asking out of curiosity here: I've always heard that fat doesn't spike your glucose at all and protein only if you a considerable amount of it. So from what you said if you ate a fatty cheeseburger (plated like a steak and without the bread) that your blood sugar will spike? I'm currently doing a Mediterranean style diet during the week and slacking off a bit on the weekends friday evening through Sunday morning. I have done keto in the past though with the readings I've done on it saying that lots of fat, some protein, and just a little bit of carbs should basically keep any glucose spikes very low. I could only handle the keto for a couple months though.
It is a CGM more or less what you would expect, insulin is the only hormone that lowers blood sugar, then you have all the stress hormones that raise it like adrenalin, growth hormone and cortisol plus glucagon for long time storage of sugars in the body. So measuring blood sugar with a CGM gives you a value between 2.9-13.5 mmol/liter that is supposed to give you picture of a rather complex system. A CGM also needs perfect access to your free flowing blood which in it self is a difficult task.