Fat kids or a far more serious problem?

A recent article in Time magazine lamented: "In 1971 only 4% of 6-to-11-year-old kids were obese; by 2004, the figure had leaped to 18.8%. In the same period, the number rose from 6.1% to 17.4% in the 12-to-19-year-old group, and from 5% to 13.9% among kids ages just 2 to 5. And as with adults, that's just obesity. Include all overweight kids, and a whopping 32% of all American children now carry more pounds than they should."
the reason, argues time is the proliferation of fast food, starbucks, video games and lack of exercise. I offer another more sinister explanation: poverty and industrialization.
Food scarcity is defined as the lack of food: you pay your bills and there isn't enough food to feed everyone. with increase of meat and produce prices, cheap carbohydrates become the mainstay of a diet. When a body consumes carbohydrates, it causes the body to produce insulin, a molecule that carries glucose into cells. Plus what the body doesn't use, is converted to fat. The more weight one gains, the risk of type II diabetes increases.
Diabetes and obesity wasn't an issue for our agrarian ancestors: before we as a nation became industrialized, we ate what we grew. There were no stores to go to except maybe a dry goods to buy fabric or sugar. There was a dry root cellar for vegetables, wheat was for flour make bread, milk was drank or turned into creme, butter or cheese. You made your own everything. Plus there was the energy invested into the farm, you had to invest 8 or more hours of heavy physical labor, building muscle and burning calories, If someone developed diabetes, it came from genes not food.
Take for instance the Gila Indians: They were, as most traditional tribes, hunter/gathers, living off the food they grew and gathered. When the Gila river was diverted, the incidence of type II diabetes increased leaps and bounds. Why? Because they were taken off their native diet and forced to live a white man's diet of refined carbs ( white bread, pasta) and little energy expended to create that food.
So is the white bread/junk food/sugar sodas /video games really the culprit? For some maybe. But it maybe a side effect of a far deeper social problem