I happen to need a lot of sodium. As in, physically require it. A friend of mine with the same medical condition has to take salt pills prescribed by her doctor because she can't bring herself to dietarily consume the amount of sodium her body needs.
Me? I was raised to consume salt to taste - if it tastes good you need it, if it tastes bad you don't. So I can happily consume well over twice the maximum recommended sodium without flinching, which is exactly what my condition requires at times.
The problem with fast food isn't that it tends to contain a lot of sodium, but that it's high sodium without tasting salty. This throws off the natural taste sensor alert that would otherwise inform you when you shouldn't take another bite of that sodium-laden stuff. As a result you need to either monitor it consciously or everything's going to go out of balance if you eat a lot of it. This is the reason I avoid any flavored electrolyte drinks - if you're sweating badly enough to need electrolytes then unflavored stuff - even just a plain water-sugar-salt solution - is going to taste fantastic to you until it begins to taste gross, and that's when you know you've had enough and should switch back to regular water or dilute it further. Your body typically knows what it needs if you just let it to its thing already. Processed food often has the goal of being really shelf stable without tasting salty, so they've finagled their way around that and that's where the danger lies.
As for me? Get be fries drowning in salt and oil, please. My body will love you for it. I can't eat most restaurant food but fries are often the exception.
I'm so severely underweight people assume I have an eating disorder. I don't. Fat, protein, and carbs are my friends whom I simply wish I could convince to stay with me a little longer...
