Apparently, this is not because these people are so wealthy - not the middle class anyway - but because the industrial or so called edible food is paid by taxpayers to be produced in abundance. As per Dr. Mercola article
If you were to receive an annual federal subsidy directly, you would receive $7.36 to spend on junk food and just 11 cents to buy apples. In other words, every year, your tax dollars pay for enough corn syrup and other junk food additives to buy 19 Twinkies, but only enough fresh fruit to buy less than a quarter of one red delicious apple.At least 30% of the Americans are overweight, outright obese, and/or diabetics. The country is literally drowning in their own fat and has been doing it for the last 30+ years. Crap food, supported by unhealthy eating habits, propagated by public education system, has brought about this disaster in making.
Read the article to get a grasp of reality standing behind GM food, an edible food, and other goods unleashed on you by the virtue of central planning.