I see this "net carbs" idea sometimes, like today it came up in a post on another site about so-called low carb bread, which I'm not so sure about.

The CW on this, if I understand it right, is that net carbs = carbs minus fiber.

So if you have 35 g carbs, but 30 of those are fiber, net carbs is 5g, so eat up!

I dunno. Something about that just doesn't seem too precise.

If I am minimizing carbs for a good reason, like insulin resistance, does my body really go "oh, this one is fiber, cool!"

What am I missing?

(Apologies if this was covered already. I did some searching and didn't find much worthwhile. It seems like this would have come up before.)