iPhone Health data shrinking

[con]

I noticed size reductions in recent exports from the Health iOS app, including these in export.xml:

- a reduction of about 1 million characters between September and November;

- a reduction of about 2 million characters and 5000 lines between November and December.

I didn't delete any workouts. I'd compare the files using Notepad++ to determine the reason but the size of the files makes this harder. Can anyone advise?

 

[con]

So with BBEdit I notice huge swaths of data missing, including recent, e.g. relating to HKQuantityTypeIdentifierActiveEnergyBurned. Anyone know why this would be intended?