Hey, me again AutumnSadie- Ketones, say from the MCT in coconut oil, are likely superior brain food that carbs.If fact, ketones help people with Alzheimer's to retrieve neuronal function. Check out Dr. Mary Newport's work (paediatrician in Florida). As you know carbs turn to glucose once ingested, but if a person doesn't take in carbs, the amazing body produces glucose from proteins we ingest! And if we include offal (NOT my personal go-to foods), we can get many nutrients (and carbs) that you'd need a truckload of greens to emulate.
I do see the 0 to very low carbs as a problem for some, but not all, people. It is a problem for me I am sure. Your suggestion re low GI foods and exercise is 'spot on'!