Banning carbonated drinks to minors?

Cigarette smoking is known to cause a higher incidence of many diseases in people that smoke for many years. However, it has been theorized that the consumption of carbonated soft drinks over many years may be adding to the epidemic of obesity and Type II Diabetes in this country. Should the goverenment ban the sale of carbonated soft drinks to minors the same way that in the 1970's the sale of cigarettes was banned from minors? Why or why not?