Warning labels aren't going to do anything aside from trigger busybody soccer moms when they go to buy their kid's cereal because they won't stop screaming for it. Taxing it is better, but still ultimately is not going to solve the root problem, which I think is the government's over-subsidization of corn and the overabundance of HFCS.

Ban HFCS/similar garbage sweeteners in all food products, and incentivize farmers to grow something other than corn. Give them grants to build all-year-round hydroponic farms to grow vegetables or something. And then from there, I think we can start to address other ailments like school lunches and the like.