If the study of rat-behavior in the presence of fatty foods can translate to humans, it suggests that pigovian sin taxes will not be enough to stop the growing obesity problem in the US. If over-eating can be like becoming addicted to cocaine, and humans increasingly tolerate pain (in the stomach and in the wallet) in order to satisfy their addiction(s), then the motivation to reduce consumption in the presence of higher prices/taxes will be inadequate by itself as a long-term strategy. After-all, coke-heads pay a hefty premium for their habit without blinking an eye.
So why isn't cocaine so prevelent? Well for one, banning a substance, while it does lead to black market activity, does work. Does this mean we should ban all fatty foods? No, I'm not suggesting that (in fact, if you were to take my peanut butter away I'd probably injure you). But perhaps there is a middle-ground? Perhaps the FDA should be given power to enforce stricter regulations of food content. Perhaps, dare I say, we need to change the way we reward children in the developing years. When I was a kid, after my mom's divorce, I had a bad habit of kicking the shit out of my cousins for no apparent reason. So, my mom took me to a behavioral psychologist who decided all my problems could be solved if she rewarded my good behavior with a McDonald's 'Happy Meal' each time. ... I don't think I need to spell out all the problems with that for you. Heck, even the way we market implies fat=happy. And why shouldn't companies market it that way... fat and sugar = big bucks to companies that rely on addictive eating behavior for their profits.
The government regulates how we safely drive our cars (seat-belts), how we safely go to work (not at age 10), how we safely drink our alcohol (again, not age 10), but the government does not yet regulate how we safely eat. Some major cities (New York) already have bans on trans fats. But obviously regulations can be problematic because they interfere with individual choice - exactly what fats are 'bad'? Where is the line?
But there are other more outside-the-box ways the government can get involved. The government could provide subsidies for 'buddy' programs. Some of us spend hundreds of dollars a year on gym coaches (think Biggest Loser), but completely ignored is that the real problem is not in the gym - it's in the home. People don't (just) need fitness experts, they need eating experts. The government could subsidize payment to dietitians etc. to basically become home nurses / 'buddies' in a family's fight to change their eating and food shopping beliefs and habits.
I'm no diet expert, but this is my two cents. I'd love to hear yours.