NEW YORK (AP) — The number of new diabetes cases among U.S. adults keeps falling, even as obesity rates climb, and health officials aren't sure why.

New federal data released Tuesday found the number of new diabetes diagnoses fell to about 1.3 million in 2017, down from 1.7 million in 2009.

Earlier research had spotted a decline, and the new report shows it's been going on for close to a decade. But health officials are not celebrating.

"The bottom line is we don't know for sure what's driving these trends," said the lead author of the new report, Dr. Stephen Benoit of the Centers for Disease...