Some say yes I say no. Theroetically it could be possible to burn fat faster, but it's not necessary. It's a marathon not a sprint.
People who do cardio without a meal have been prone to things like dizzy spells, or find they couldn't finish a workout, they got too tired. There was apparently even a report once of someone having a seizure, but that was an isolated case.
Think about it, you have low blood sugar first thing in the morning, so you do something that will reduce Bloodsugar anyway, by utilising sugars like Glucose and Glycogen, but as you're stomach is empty, probably Glycogen only. I'm not including other stuff like ATP for example, just things you could call Sugar energies.
Logically this doesn't make sense. To combat the issue, give the body some sustenance for fuel to make things better for yourself.
Plus without sustenance you could burn Muscle too.
Fasted Cardio to me and many who post here is a no-no and if it was the only way to get to a certain level of body Fat maybe, but it isn't. You can still lose the fat and get good bodyfat level anyway, without doing fasted Cardio.
People got 6-pacs before Tom Venuto wrote books about it and without Steroids too and they didn't all look like bits of string either. Admittedly beyond a certain level of muscle build, you'd need steroids to get a 6-pac, but certainly even as high as 170lbs-175lbs, you should be able to get 8%-12% bodyfat, without fasted Cardio, so basically don't do it.