Hi, tolsn. I'm prediabetic (but think of myself as diabetic). I don't think there is a standard "those are good numbers" or "those are bad numbers" because it depends on what stage of control you are at, so you may have to figure out the best numbers for you on your own. I do believe, however, that at that level, those numbers are associated with diabetic complications.
If it helps, I test upon waking. Then before each meal. Then one hour after a meal, then every hour until it's back to about fasting (5.4ish these days for me). My peaks occur at forty-five minutes to one hour, or sometimes at two hours if the meal was a large one with significant carbs. I want to know how high they're going and how quickly it takes to get them down.
To my dismay, in tracking my blood glucose levels after meals, I started to notice I was getting high blood sugar reactions (like sleepiness, false hunger cravings, digestive disturbances) when my blood sugar rose by as little as 1 mmol/l at the post-prandial peak. That's not very much of a rise to cause reactions, so I've tried to keep it down since then - especially as Dr. Richard K. Bernstein, who's pretty extreme but seems to have great success in treating diabetes, recommends no more than HALF of that level of rise!
It's a really good idea to test as often as you possibly can (even up to every half hour after a meal) to figure out how long it takes you to get back to fasting blood sugars quickly after a particular meal. The shorter the time, the better - because imagine how high your blood sugars rise if you eat your next meal before you've gone down to fasting levels! And that's unfortunately likely, because high blood sugar can give you false hunger signals!
Then, if you want to tackle this by diet, you might do adjustments to your carbs/fat/protein ratio to see what gets you down to as-close-to-normal blood sugars as possible. For me, that means reducing the carbs, increasing the fat, and keeping the protein the same or add more, as needed.
Before I started changing my diet like this, I'd been getting 1-hour readings in the 8's and 9's and even one in the 10's. These days I'm rarely as high as 7 and often under 6. Once again, those happen to be my numbers at a level where I don't get blood sugar reactions. Different people use different criteria for what levels to aim for, I gather.
