Hi
welcome to the forum..... There are lots of threads on the forum for you and hubby to read. Loads of education ....
Regarding your post ..........sometimes, bg levels do change for us all using insulin. That's not at all uncommon. Sometimes, there is a reason and sometimes there doesn't appear to be, it's just the way the body changes its needs.
The only thing I can suggest to you to do is look at the times hubby's bg levels go up and then look at the amount of carb that has been eaten 2-3hrs earlier. There are 2 things that you can do that will alter bg levels and that is .... 1) is to eat less carb or 2) inject a tiny bit more insulin. You will of course need to test bg so that you can see what effect the changes you have made will have on hubby's bg levels.
What insulin is hubby using? If he is injecting 3 times a day, is this using mixed insulin or is he using bolus/basal?