Lots of mentions of brain fog as a by product of eating a processed food/carb heavy diet by those who favour a LCHF diet. I've always thought it was a bit psuedo science myself (even though I like LCHF) and is just used as a way of promoting that type of diet.
I think the issue is more if you eat a heavily processed diet. If the carbs you are getting are coming from whole food there should be less of an issue. Try cutting back on carbs for a few days maybe? Up the protein and fat to compensate and see how you feel.
Lots of mentions of brain fog as a by product of eating a processed food/carb heavy diet by those who favour a LCHF diet. I've always thought it was a bit psuedo science myself (even though I like LCHF) and is just used as a way of promoting that type of diet.