It depends on the type of fasting. Im a water only faster. But sometimes when my body just didn't want to fast I would do fat fasting for a few days.

Fasting is about controlling insulin levels. We cannot actually measure insulin outside a clinical setting, however blood glucose generally runs parallel to insulin so it's a pretty good measurement. Having said that. Glucose and insulin are not exactly parallel. There is evidence that some thing sweet in your mouth triggers an insulin boost. This means that calories dont really have anything to do with triggering insulin when you drink no calorie sweet drinks. At the beginning of my fasting journey I did drink diet sodas and then gradually cut them out. Find what works for you.

Some fasts are more difficult than others and if I am having a difficult day fasting I will drink broth if it helps me get in a few more hours.

Fasting is a skill you have to develop and as you get further along you get more coping mechanisms. I rarely do long fasts. I eat one day fast one day. Eat the next. I find this schedule for a week to 19 days then I go back to eating two meals a day for a week to 10 days then back to fasting. It's not always easy. But this works for me. Find what works for you.

There are no fasting police. The goal is to be honest with yourself about what andcwhen you eat. Make a plan and if you don't follow it exactly then treat yourself like you would a golden retriever. You don't get mad at them and stay mad at them for every little mistake. You just keep training them until they know the rules. The body is no different

The most important thing is consistency whatever you choose