Wheat and sugar are oft-cited culprits in the obesity epidemic. This isn't going to be a science-backed post -- although I've read a good deal about this. This is more an observational post.
I'm was a child in the sixties and early 70's. Raised in a "healthy household" we didn't eat Wonder bread and Sugar Frosted Flakes (back when you could use the word for what the frosting is made of!), but most of my classmates did. I look back at class pics from elementary school and there's one or two "fat kids" -- by today's standards these kids aren't even all that large. And yet, I think back on what most of my classmates had for snacks -- fruit rollups (yeah, not much fruit in those) and saltines were big items. For lunch it was usually a sandwich of some sort on white bread (PB&jelly were as popular as cold cuts), milk or juice, and a Twinkie or cookies. Does anyone remember Pixie stix and Lick'm'ade? These were nothing more than straws full or pots full of colored flavored sugar. We didn't have sodas as much, and the juice box had yet to be invented, but small cans of juice were popular. When I would go to friends' houses after school usually I got a glass of lemonade or punch made from a sugary mix. Anywhere refreshments were provided usually included "bug juice" (KoolAid). Tang was pretty big too. Breakfast at a diner wasn't just bacon and eggs, it was pancakes (with butter and lots of syrup), waffles (same), etc.
Bottom line: Refined carbs were accessible and consumed. Margarine and veggie oils were already in fairly widespread use -- I don't remember my friends' Mom's cooking much in lard and tallow. Although my Mom tended more toward whole grain breads (sprouted often times) and brown rice, she didn't soak or ferment grains and such. And I actually don't remember the Buttertons either, although fat phobia hadn't set in.
So why did my generation not overeat similar foods on a regular basis while we do today?
Why didn't being subjected to such foods cause obesity in us kids? We're often convinced that kids get addicted to sugar at an early age and eating these refined carbs is driving our hunger is causing us to eat 150-350 more cal/day on average. I'm sure there are those with greater sensitivity to these things, but something else would have to be responsible for a dramatic increase in the proportion of these people in the population to finger these foods specifically as triggers for overconsumption and obesity.
I can identify a number of lifestyle changes in our culture as a whole that have allowed for overconsumption of such foods. I tend to believe it is these changes, and not the macronutrients themselves or government recs, etc., that are responsible for the obesity epidemic amongst children in this country.