So calories may have nothing to do with the obesity epidemic: if so, what does?

So my earlier intuition, based on mere observation, that calories had nothing (or very little) to do with the obesity epidemic, has now been shown to have been correct:

"Despite obesity rise, U.S. calories trending downward March 06, 2013 01:32 PM ET NEW YORK (Reuters Health) - U.S. adults have been eating steadily fewer calories for almost a decade, despite the continued increase in obesity rates, according to survey data from the Centers for Disease Control and Prevention (CDC)." http://links.reuters.com/r/CRB2Q/7HA2Q/08U5ZC/V11JD5/3C632Q/YT/t

That leaves unanswered the question: so what IS responsible for the obesity epidemic?

As earlier, I suggest that food modification may have something to do with it...as well as the kinds of fertilisers used.