How am I healthy if I eat a terrible diet?
It takes time for some problems to show up. Type 2 diabetes, for example, doesn't take hold after just a month or two. The build-up is slower: first there will be insulin resistance, for example.
Same with deficiency diseases, kidney problems, and so on. Generally the weak points are due to genetics, with a poor diet allowing the genetic weakness to burst forth.
In The Magnificent Seven (the one with Yul Brynner, Steve McQueen, et al.) the McQueen character tells the story of a man who fell from the room of a 12-story hotel in El Paso. As he passed the fourth floor, he was heard muttering, "So far, so good."
So far, you're not showing any problems.