I have lots of foods I don't tolerate. Mostly high carb foods like all grains, starches, sugars etc so no problem there being low carb for me.
I also don't tolerate a lot of fiber but I do tolerate very well avocado. I eat one a day but split throughout the day. It also helps keep my sugars down by a lot.
I don't tolerate lots of veggies either. So I eat a very high fat, very low carb and moderate proton diet. I think I'm missing the gene that digests carbs. I've always been this way long before diabetes.
Eating four small meals helps me too.
Bf is either 1/3 avocado or a thin slice of deli turkey / chicken on a lettuce wrap with mayo and mustard.
The next three meals all have avocado and protein. Some with mayo or extra virgin olive oil.
Snacks are a few nuts or pumpkin seeds, olives, or a few raw veg.
I have a large variety of proteins that accompany all meals in small amounts.