Addressing the source of the issue would mean lots and lots less money for those behind the funding of things like a FREAKIN' OBESITY VACCINE to keep from addressing the source of the issue.
"My fat, lazy, ignorant fellow Americans...now instead of worrying about pesky things like good diet and exercise, which lower your risk for health problems that make us money and lower your spending on products that increase your health problems that make us money and make us money...here is a vaccine which *might* keep you from becoming obese but will *certainly* cause you even more health problems whichmake us money and make us money and MAKE US MONEY. Rejoice! Eat! SPEND!!"

The vast majority of people who hear about this will add it to their wish lists, give up on already pitiful attempts at caring for themselves, fork out the dough, get even sicker, and get pissed and punitive at anyone who doesn't follow suit.
The bull is definitely not stopping. What next? A vaccine for thinking?
I'd say we've already gone there.