Do keep in mind that being 'pre-diabetic' does NOT mean you've got to commit to a life on lettuce! My Dh is Type 2 and has learned lots thru diabetes classes sponsored by our local hospital&diabetes assn, which were covered by our insurance w/a very low fee.
I guess it depends on how much your own DH wants to admit that he mite have a problem? Because of these classes, my DH lost about 50+ lbs just by changing what he 'nibbles' and portion control, plus minimal meds. Really.
Remember you can't police him? You can provide the good [healthy] stuff to 'nibble' or other stuff. Maybe both. But IF he is truly aware and wants to live and maybe even feel better....well it's all going to be HIS CHOICE! You can't be the food marshall here- that won't ever work, and you both would be miserable for it.
PN damage issues from diabetes can be halted, slowed down or eliminated due to the lifestyle changes, but it's got to be up to the principals to make the changes. No one else can do it for them. Plain and simple. You can only be there to HELP. As best you can, when you can. 's - j