I'm using an iPhone XR with IOS 13.3 and accidentally deleted my Health app data. I have my phone being backed up on iCloud. Is there a way to restore just the Health App data without resetting and restoring the whole iPhone?
I think you have just disabled Health data from your iPhone. The solution is pretty simple. Open Settings > tap on your Name > tap iCloud > and turn on Health toggle under APPS USING ICLOUD section. The method just syncs your health data to iCloud. If you have accidentally deleted health data from the Health app, it is impossible to restore the same to your iPhone. If you can elaborate how you have deleted the health data from your device, I can guide you better.