My husband had this and it was a sign of type 1 diabetes (which he developed at 26 years old, so just because it's known as juvenile diabetes doesn't mean you can't develop it later in life). He is the only person I've personally known to have this. BUT, his breath didn't smell "fruity" like fruit, it was a very very sweet smell, sickly sweet. And he was exhausted all the time and his vision was blurry and he was peeing all the time (including waking at night to go). If you have any of these other symptoms see your doctor or invest in a glucose monitor and check your sugar levels. If it's just your breath my guess would be it's a product of your diet. Sorry for the long answer.
~*~*~Don't let today's moment forsake tomorrow's dream~*~*~