"The American diet is very bad."
Translation:Amerikansk kost er meget dårlig.
why isn't it "den amerikanske kost"? Why do you drop the definite article in this case?
It's not needed; you can include it if you want but you don't have to. If you do, you're adding stress to the American diet, and frankly, I think it's under enough stress as it is :-)
I don't really know why, but I know that "den amerikanske kost" is entirely correct.