Triage exists for a reason, and it seems reasonable to apply that here. If you want to accept the risks of your “lifestyle choice”, you should be the one who faces the consequences by being lower in priority for healthcare. If I exercise and eat right, when I need an ICU bed I should be given priority over someone who accepted the risk of eating fast food three times a day, surely?
Regardless of the moral issue, due to EMTALA hospitals are legally required to care for unstable patients regardless of whether they made unhealthy choices. Changing that would require an Act of Congress.
You can dump covid patients with low odds of a positive outcome off support equipment (vents and ECMOs) when healthier patients come in for treatment and equipment supply is constrained. This is already occurring (crisis standard of care).
I'm guessing that's eligible population as the numbers mentioned in the article line up more with around 66% of the total population, which isn't enough to stem the tide.