Why stop there? We might want to monitor people each day via fitbit like devices that report back the data to ensure everyone is exercising the recommended amount. We can then tax or reduce taxes for the applicable individuals.

This could obviously be deemed a bit of a slippery slope fallacy, but I'd argue the above is probably more beneficial than taxing my soda if you truly want to reduce healthcare costs by having healthier individuals. But, who wants to go that far?