I’ve completed two 72 hour fast episodes now- separated by 90 days- due to prompting from my low-30’s daughter Amanda. The idea was daunting for someone accustomed to regular meals but it turns out the normal , healthy human body is remarkably adept at managing energy intake and usage. For me the most difficult part was skipping that first mealtime. After that hunger was really no issue and increased mental acuity and an accelerated sense of the passage of time were remarkable. I spend considerable time cooking so had expected the time normally spent preparing and consuming meals to drag by while fasting. Not so at all!
I used a low-carb electrolyte replacement powder in water and went on with my everyday farm activities with seemingly more than normal intensity. Sleeping thru the night was improved. Skipping the first meal was easier if another activity was planned to displace it.