I’m not talking about the “typical” junk food (like KFC or McDonalds), instead it’s more on certain aspects of Japanese cuisine being carb heavy or features fried items such as: ramen, agepan, karage, tempura, gyudon, tonkatsu, yakitori, etc. I mean, can ramen or gyudon bowls still be deemed “fast food” even though they appear ‘healthier’ than American fast food.
I think McDonald’s kicked off term “fast food”. Street vendors selling hotdogs and other stuff predated them, so your definition is also what I’ve gone by.