Insulin resistance is like very early stage type II diabetes. You can do a bunch of things to help improve your insulin resistance, including both drugs (e.g. metformin) and diet.
Interestingly enough, my husband was trying to fight his type II diabetes by having no carbs at all and it wasn't really working for him. He's now actually incorporating some carbs (even the dreaded potato) into his diet and he's both lost weight and really improved his blood sugar. The key for him was eating frequent, small meals (all containing protein) and making fruit & vegetables a big part of his diet.
This is all a long-winded way of saying that IBS-safe fruits and veggies, along with protein at every meal, might help a lot and allow you to have some white bread or sugar on occasion. Plus, my husband had to go out and buy jeans two sizes smaller this weekend because this diet helped him shed some weight!