My insurer's discount scheme is pretty elaborate. There are small reimbursements for non-smokers, using a pedometer or bicycle odometer, submitting cholesterol and glucose test results, shopping at the farmer's market, etc.
I support nudging these ideas onto folks' radars, but in the grand scheme medical expenses are such a colossal mess I'm not sure how to sort my thoughts other than "avoid avoid avoid". Just yesterday our paper had an exposť on which local clinics and hospitals charge 400~800% more for identical services compared to their neighbors a half mile away, and patients have basically no prior access to this information.
Lots of: urban hiking, cycling, sprinting
Lots of: fresh meat, seafood, eggs, organs, tubers, starch fruits, vegetables, meat fat, dairy fat, oil fruits
Some: cured meat, dairy protein, sweet fruits, rice, pulses, tree nuts, oil seeds
Minimal: soy, refined proteins, sugar, liquid carbohydrate, grains, refined oils, peanuts