It is purely a health issue. Since smoking is clearly bad, it should be banned in all forms, in all places. That said, obesity kills far more people in this country than smoking. In light of this, I believe it only makes sense to also ban fattening and unhealthy foods. All fast-food should be eliminated as unhealthy, all fried foods, and all citizens should report to diet stations where they will be assessed for the proper intake of nutrients - those deemed overweight will face criminal penalties for not losing weight or failing to comply with government-ordered exercise plans. Uberfatties will be imprisoned until healthy enough to roam free again.
It has been and always will be the job of the Government to identify what is in your best interest, and to force you to comply with its findings.