Another factor (my Pet Theory actually) about obesity, especially in Americans and others in warmer climes is Air Condidtioning. If your body thinks it's perpetually October, it will signal for more food/fuel. In the South, there was once a thing called the "cold supper"- tomatoes, other veggies & some leftover chicken perhaps. Who wants to tuck into a 1/2 lb slab of meatloaf & a pile of spuds when it's 95 (farenheit) degrees? The body will tell you what it wants if you listen to it. Ignoring natural rhythms & cycles and dumping pure crap into yourself is a sure bet for obesity & worse.