Abstract out the obesity, and you've described every chronic health condition, ever. A huge number of emergency room admissions read something like: I thought it was normal that road signs were getting a little blurry after 40. Sure my heart screams in agony when I climb stairs, but who's doesn't? My knees are in crippling pain for days if I hike more than two miles. Every time I drink, I drink till I pass out or are arrested, but doesn't everyone? After I eat sugary food (aka modern american diet) I feel faint and fuzzy, that's normal, right? I hear voices in my head more often as time goes on. Why how odd that pain pill has smoothly and gradually gone from something to make life bearable after surgery, to life is unbearable without it, to life is unbearable even with it.
People tend to be pretty good at getting medical care for acute things like bleeding out more than a quart or so, or broken bones, but not so good at getting help for chronic things. Gettin fat is obviously not an acute problem.
That's assuming you're buying your own food; if you're eating in a restaurant or something you don't even really know what you are consuming.
I guess just like real-talk sex-ed went against the interest of big-church, teaching some basics when it comes to nutrition would hurt a lot of big-food...
To me it's more like the current environment, to borrow a programming term, makes it difficult to "fall into the pit of success."
The NYT ran a great article on this a few years ago: http://www.nytimes.com/2013/02/24/magazine/the-extraordinary...
It's not like we're rationally considering each small action. Instead, at any time, in a give society, there are a set of behaviours that are considered within the normal range. We're mostly on autopilot.
Most of the time the difference between steady gaining or losing weight is a few hundred calories a day. That's far from a lifestyle change.
When moving around becomes difficult, when dating becomes harder, when the aches and pain start... there's gotta be more to it than just a lot of sugar in your everyday stuff.
I always wonder (for other drugs too), if they're a way to slowly remove yourself from situations, or whatever it is, that make you uncomfortable. A way to permanently disqualify yourself from the race, because the idea of running (no pun intended) makes you anxious?