I suspect the best health outcomes would come from abolishing not just DST but time zones altogether.

Time zones made sense when the steam engine and railroads were how people travelled - local times made a mess of printed timetables. These days, we're all carrying what in the 60s would have been a supercomputer in our pockets (and many of us have a 90s era PC on out wrists) local time is entirely feasible.

Back in the Middle Ages, hours were variable: the transitions between light and dark were 6 (AM and PM) so hour lengths were variable. I'm not suggesting variable hour lengths, but there's a lot to be said for setting something like 6AM to dawn, sticking to a standard 60-minute hour so for most of the year, 12 'noon' wouldn't be 'high' noon, nor would 6PM mean the sun was down - but all of us on 'day' shift would not be getting up at oh-dark-thirty when daylight got shorter.

Just a thought...