I don’t know the post you’re talking about…but it depends on the definition of “you.” If it’s just everything that’s inside of the space enclosed by your skin, then you would indeed be 1% nacho in the moment after eating a pound of nachos.
However, the nachos are not “you” in that they aren’t your cells, and they don’t have your DNA. Though, that would also go for the bacteria that you contain, which make up about 3% of our mass, and all of the interstitial water that isn’t enclosed by your cells (I’m guessing another 20% or so)
However, in an interesting way, your digestive system is kinda not “inside” you. It is very much a tube of outside that runs through our insides. It’s a long and complicated tube, and our body has a lot of control over it, but we’re all kinda just long doughnuts with a mouth on the top and an anus on the bottom.
So, in that way, the nachos are never really “in” you. Molecules of fat and carbohydrate and protein will be absorbed, but the nachos are “outside” of you until they’re broken down into something that is definitely not nacho before being absorbed.