Idk how much of purist yall are. Dr Jason Fung says if you are really trying to hit that 72hr fast you can have a cup of coffee with coconut oil or unsweetened heavy cream to help you ease into it. Since fat generates the least amount of insulin it
Everyone is different. I try to stay under 40g of carbs and I personally try to avoid all highly refined carbs as they make me feel terrible. Good luck. #1 goal should be consistency. So find something you can stick to ie Omad or rolling 48s.