[blfr]

Check the studies you're relying on for this information. Most are confounded by people simply eating fast food.

[quickthrower2]

And fast food is different because… ?

[blfr]

Lots of crappy carbs and added sugar on the side with generally low quality ingredients compared to what anyone caring about their diet would eat.

Most people don't have the dedication of a body builder carefully eating only patties from the burgers. Which would probably work.