Personally I suspect this documentary as true. Americans are the fattest people on the planet, and I'll tell you that compared to Japan, American food is overall crap. I've seen more fat people in the States in a day than in Japan in a year. Sure, American food does taste better than Japanese food, but far unhealthier. I've been of the belief that deregulation of food companies, and the allowance of them to put all types of chemicals / preservatives has destroyed its nutritional value.
As fat as Americans are now, I am convinced the trend of obesity shall continue..