Thanks for the question.
It is conjecture; however, the University of Waterloo did a study looking at the financial benefits of implementing a tax on sugar-sweetened beverages. I don't have the study in front of me, but it seems to me it was close to roughly $1 billion per year over 25 years in health care cost savings because of the role of excess sugar in the diet.
The benefits will be there, absolutely. The cost-benefit analysis is pretty clear that there certainly are benefits in reducing the incidence of childhood overweight and obesity as well as from improving nutrition as physical activity.