I was listening to a podcast that had Jimmy Moore on as a guest. As they’re talking, Jimmy very clearly stated that he thought that it was a total mistake to not count total carbs and that people who were counting net carbs only could be boobytrapping their ketosis.
Which is correct? Not counting Fiber makes total sense. Not so sure about sugar alcohols.
Can someone show me the science on this one?
It’s actually not a matter of science in this case, unless it’s “the science of @thatedeguy.” @Brenda will tell you there’s one rule in keto - there are no rules.
As you cruise the web, you’ll find as many differing opinions on many aspects of the keto way of life as you find websites. You have landed in the “kinder, gentler” environment that 2KD set up, lucky guy!
What I’m saying is, around here you’ll find folks who do it both ways, shoulder to shoulder with folks who count SAs and folks who don’t - because it’s left up to you to find what works for YOUR “N=1” experiment with keto. Every one of us is a special snowflake. 
Start out not worrying about it, how’s THAT for an answer? 
Eat protein in moderation (a nice serving each meal), load up on fat, and eat just incidental carbs. Eat til you’re full, using fat to satisfy. If that seems to be working, it ain’t broke, so don’t fix it.
If you’re bogging down, constipated (there’s a topic for that 
), feeling terrible, or whatever, tweak your N=1 using suggestions here to get the engine chugging again. No one here is the “Net Carb Police.” It’s your bod; do what makes it feel good.
science? well… biologically most of us have a gut biome that does not digest fiber and turn it into glucose, same with sugar alcohols… but some of us CAN!
there are some people who can partially digest sugar alcohols and see a blood sugar spike.
Enter n = 1
As much as we all want concrete set-in-stone guidelines sometimes, they aren’t always there.
I like to use net carbs for the food that has fiber. The best case is the avocado. One avocado has 17 grams of carbs and it looks like it should not be included in the diet but when you realize that it has 14 grams of fiber and the net carbs are only 3 grams, it invites you to have one. You know what they say, an avocado per day keeps the doctor away. I cut one in half, remove the seed, add salt, and eat it with a small metal spoon. Avocados are loaded with potasium and faaaaaaat!
Thanks all! Bottom line I’m getting from all of you is to just use what works. And since it seems to be working for me as I’m doing it, I’m not going to worry about it too much. For the record, I’m not counting net carbs by taking fiber and sugar alcohols out of the total carb count. So far, I’m three weeks in, and 20 pounds down, and feeling good.
EDIT: I should have proofed a little bit there. For the record, I AM counting net carbs rather than total carbs. I’m taking the total carbs and subtracting fiber and sugar alcohols out. (Using Cronometer for all the heavy lifting.)
Personally, I have had excellent weight loss results so far (a little over a year of keto) and count net carbs.
There are 3 good reasons to substract fiber from the carbohydrate count for a net carbohydrate calculation. These 3 reasons do not apply to sugar alcohols. 1) To include some good low carbohydrate vegetables that would be excluded, for example the avocado and the tomato. 2) Substracting fiber from the carbohydrate count would increase the intake of fiber. This is good. 3) Fiber does not increase blood sugar levels. Dr. Bernstein specifically removes sugar alcohols from his diabetes diet because they increase blood sugar. See his list of “stealth sugars”, it includes sorbitol and xilitol.