Do I have to click the app to get it to register overnight fasting times?

I'm a Gold member.

I'd like to have a report for how long I've fasted, on average (without trying), overnights.

When I click on fasting, it seems I have to "start a fast" in order for the app to register that I'm not eating? Is there a way the app can just tell me my average duration without eating, the same way it tells me my average macronutrient intake?