I can't agree with it being a delusion. Again, my personal experience is just that -- personal.
Ketones are associated with fasted states and/or restricted carbohydrates. The average person holds about 400-500g of glucose (1600-2000 calories) in their bodies. Once that is depleted, through fasting or carb restriction, you will switch to ketogenesis to provide fuel. There are numerous studies that show a positive correlation with ketone production and cognitive performance.
If I am doing serious deep work, I can go 8 to 10 or so hours without even thinking about food. However, once I do eat, I'm done with any serious work for a few hours. Keep in mind, I'm operating from a 20 year experience of intermittent fasting (before it was cool).
To reiterate, I don't think it's a delusion. We evolved in a feast or famine state. Dense carbohydrate sources and constant satiation were rare when our base metabolic pathways evolved.
> Castellano, C.A., Nugent, S., Paquet, N., Tremblay, S., Bocti, C., Lacombe, G., Imbeault, H., Turcotte, E., Fulop, T., & Cunnane, S.C. (2015). Lower brain 18F-fluorodeoxyglucose uptake but normal 11C-acetoacetate metabolism in mild Alzheimer's disease dementia. Journal of Alzheimer's Disease, 43(4), 1343-1353. doi: 10.3233/JAD-141952
-- This study found that the brain's uptake of ketones was preserved in patients with mild Alzheimer's disease, and that higher levels of ketone metabolism were associated with better cognitive performance.
> Krikorian, R., Shidler, M.D., Dangelo, K., Couch, S.C., Benoit, S.C., & Clegg, D.J. (2012). Dietary ketosis enhances memory in mild cognitive impairment. Neurobiology of Aging, 33(2), 425.e19-27. doi: 10.1016/j.neurobiolaging.2010.10.006
-- This study found that a ketogenic diet improved cognitive function in patients with mild cognitive impairment.
> Taylor, M.K., Sullivan, D.K., Mahnken, J.D., Burns, J.M., & Swerdlow, R.H. (2018). Feasibility and efficacy data from a ketogenic diet intervention in Alzheimer's disease. Alzheimer's & Dementia, 4, 28-36. doi: 10.1016/j.trci.2017.11.002
-- This study found that a ketogenic diet was safe and feasible for patients with Alzheimer's disease, and that it improved cognitive function in some patients.
Granted, these are studies for people with existing cognitive impairments. However, given how new the science is, I can see why it hasn't been done with healthy individuals, yet.
Ketones are associated with fasted states and/or restricted carbohydrates. The average person holds about 400-500g of glucose (1600-2000 calories) in their bodies. Once that is depleted, through fasting or carb restriction, you will switch to ketogenesis to provide fuel. There are numerous studies that show a positive correlation with ketone production and cognitive performance.
Few examples: > https://pubmed.ncbi.nlm.nih.gov/25404320/ > https://pubmed.ncbi.nlm.nih.gov/27528626/
If I am doing serious deep work, I can go 8 to 10 or so hours without even thinking about food. However, once I do eat, I'm done with any serious work for a few hours. Keep in mind, I'm operating from a 20 year experience of intermittent fasting (before it was cool).
To reiterate, I don't think it's a delusion. We evolved in a feast or famine state. Dense carbohydrate sources and constant satiation were rare when our base metabolic pathways evolved.