I am doing 18 hour fast each day and I have been timing myself from the moment I finish the last bite of my last meal. However I began to think that this really isn’t the start of a fast since I have food in my stomach. Also, technically, my body has source of energy for hours to come still. Does everyone mevertheless count the start of a fast as the last meal is finished?
Yes. After your last bite. That’s something you can control. You can’t control or easily measure your stomach emptying, etc.
Also, I would hope you have a source of energy for hours. Otherwise you wouldn’t be able to fast any amount of time.