What I want is a change to insurance industry regulations to make it so fat people and sedentary people can start paying their fair way and not be subsidized by those of us who maintain their health.
Could be done a number of ways. Life insurance already sometimes requires a physical at signup. Why not for health insurance too? Could also just be a discount. Could even, e.g., partner with Peloton--you work out 5 days a week? Actuarial table shows you're XX% cheaper to insure.
If it's opt-in like that, all the healthy people will opt-in, and all the unhealthy people (NOT pre-existing conditions, just things within people's own power to control that some do well and others ignore--exercise and diet, primarily) will pay more.
No need to tax the sugar, tax the actual impact, healthcare.