Interesting question. I think the answer lies in the insulin index but I’m no expert. People often incorrectly assume that a ketogenic diet optimally lowers insulin resistance. That’s not necessarily true as I understand it. There are many foods that are highly stimulating of insulin that are keto staples. A great example is beef. It has basically 0 carbs, so it’s great for keto, but it has a very high insulin index score (50), so it’s terrible for addressing insulin resistance. Conversely, a can of navy beans has tons of carbs, so it’s terrible to for keto, but it has an insulin index score of 23, so it’s excellent for addressing insulin resistance. Incidentally, a poached egg has an insulin index score of 23 just like navy beans. Even more surprising, although white pasta is a keto nightmare food, it has an insulin index score of 29, vs beef at 50. We could debate whether different cuts of beef have different insulin responses (they do), but the point remains (I’m not anti-beef btw, I’m just anti-insulin resistance)
When you look at the actual published data on what triggers insulin response, a lot of it is intuitive, but much of it is surprising. What’s good for keto is not necessarily good for managing insulin resistance. When it comes to maintenance, I care a lot more about managing my insulin resistance than I do about maintaining ketosis gratuitously. Some folks don’t have that luxury due to epilepsy, autoimmune disease etc, but my main problem is insulin resistance.
Here is the most definitive table of foods with measured insulin index that I’ve ever found. It’s worth reading if you are thinking about managing insulin resistance and/or maintenance.
In answer to your actual question, different breads have different insulin index scores. White bread had a score of 73 in Bell’s table above, but Holt et al. measured rye bread (47% kibbled rye) at just 56. I think there are definitely breads out there that are compatible with maintenance, but I’ll probably just stick to beans personally.