I remember reading a small study on this a few years ago that had concluded that the way your pee smells after eating certain foods is genetic (big surprise), so the foods that make your piss smell may not make someone else's piss smell. In the same research they had hinted that perhaps our interpretation of how piss smelled was even highly influenced by genes as well, so perhaps you can find someone who thinks your piss doesn't smell at all...
But the basic answer is: it smells that way because that's how your body works and you're stuck with it
Is it only for "canned" fish/meat? Perhaps avoid that in the future.