The average American now eats 1/2 lb of sugar per day - 15% of total calories, and another 7% or so from soybean oil (sometimes sold as "vegetable oil"), a substance that did not exist in 1970. That's a quarter of your daily calories from inflammatory GM PUFA and sugar.
That might have a bit more to do with obesity rates than 33 lb of cheese per person per year. I ate cheese all through my weight loss period, though I did cut it back substantially.
Those ads make about as much sense as invading Iraq in revenge for 911.