For all the people who never heard about FODMAP: it is probably worth to check this out if you have regularly stomach pain, bloating, diarrhoea and constipation.
I had IBS before going on a keto diet - Keto fixed the problem. I've never specifically tried low-FODMAP foods.
I think I concentrate better on keto, but I suspect that's because the brain likes ketones better than glucose. I have no idea whether low FODMAPs make any difference in reducing chess blunders. But I have to say, if I was trying to get rid of my IBS, I'd worry much more about that issue than whether it helps my chess.
For all the people who never heard about FODMAP: it is probably worth to check this out if you have regularly stomach pain, bloating, diarrhoea and constipation.