I'm totally with Frenata on this one. I think it is a regular old ugly epidemic caused by some bug or something, and folks are so blinded by the "we're eating junk/too much food/not exercising enough/lazy slobs" thinking to really figure out what's up.
Clealy, I agree that eating junk/too much food/not exerrcising makes things worse, but I think it's manifestly a stupid infectious agent or some other thing that screws up the digestion/metabolism of affected folks, making us ridiculously susceptible to weight gain. Exactly as Frenata has pointed out, all those folks before us ate CRAP food, and "too much" of it, and "didn't exercise enough", yet stayed reasonably slim, or could lose weight with a modicum of effort.
I for one haven't eaten junk food in years. (How'd I manage that? I left the States at the beginning of the Bush administration. (Not related to that: that's just how I remembewr when I left.)) I eat healthy home-cooked, mostly vegetarian, predominately VEGGIES, tofu, etc. I lift hella weights. I am still fatter and heavier than I was 6 years ago, and in "obese" territory. SLD definitely helps, but it is a slow go for me.
You should see what happens to me on my yearly trips back to the States. I eat out a bit with my folks; I have a coupla slices of cheesecake over the visit; I gain TEN PLUS POUNDS in one month!! Even here if I eat restaurant food ONE NIGHT I will gain pounds.
Meanwhile, my skinny hubby eats crap and remains skinny. He eats that restaurant food many times a week. He also does not exercise or lift weights.
Anyway, what to do. Keep getting fatter or fight it with whatever helps our whole lives until a real understanding and cure is found. Sigh...