It sounds a lot less sinister if you rephrase it:
And those who reach targets in three categories get an extra $1,000 on their paycheck, that comes from the discount on their health insurance.
This kind of data should not be known/tracked by your employer ever, for reasons of privacy. That's totally different from your health plan knowing, however.
The deep question here, regarding all health insurance (including national schemes), is -- to what extent should you be expected to subsidize other people's intentionally unhealthy life choices? To what extent should people who make these unhealthy choices be forced to pay more for them? If I get diabetes because I drank 20 cokes a day...
But it gets even harder, because who defines healthy? The long-term effects of so many activities is so unclear, or under so much debate -- just like sugar, for example.