Most of the time when people try to define healthy food vs. junk food in a fair and unbiased way, the line gets drawn at "whole foods" vs "processed foods".

A typical burger meal is definitely processed food because the meat is processed mechanically and mixed from different sources (usually with added fat); the bun is made from refined flour and refined oils; and the fries are thinly-cut potatoes blanched and fried in more refined oils. (Not to mention a whole bunch of chemical additives which are the norm rather than the exception; and "hyperpalatability" tweaks which means the food is formulated to taste unnaturally good.)

You could perhaps argue that a home-made burger meal made using whole cuts of meat, a lean wholemeal bread dough, and potatoes roasted in animal fat could count as a healthy/whole food meal, but it would taste different to the typical hamburger meal we all associate with fast food.

Fast food also has an enormous marketing industry behind it which pushes it in unhealthy volume, with maximum convenience, and at (until recently, at least) affordable prices.

(to all the boolean questions): yes, yes, yes, yes, yes, yes, yes, yes, yes.

Is there evidence supporting the idea that sugar is more satiating? My understanding was that they were equally unhealthy

Real sugar in your soda pop? What are you, a health nut? Must be a real my body is a temple sort.

Seriously though, it's a dogshit thing to consume whether it is sweetened with HFCS or sucrose.

"Even today, a Soda with 'real sugar', at least for me, is far more satiating"

Did you know that in the acidic environment of a cola, sucrose quickly degrades into fructose and glucose (and if it didn't, your enzymes literally immediately crack sucrose into them). You know, exactly the same fructose and glucose that would be added by HFCS. The proportions differ a tiny amount, but this notion that one is satiating and the other isn't should really send you down a path of self-discovery, where you determine how you fell for nonsense.

What's interesting is that it's different parts of the electorate that get upset. When Republicans wanted to make junk food/soda ineligible for food stamps, Dems got upset. And when Dems wanted to tax large sodas, Republicans/libertarians got upset.

I think the former makes much more sense than the latter, since it is literally being funded by the govt. That's a reasonable first step, or possibly only step, especially considering that most people on food stamps are also on govt-funded/subsidized healthcare (meaning taxpayers will end up footing the bill when they require expensive treatments resulting in part from an unhealthy diet).