Rosenicola
Sorry - but this is fruit, but hear me out...
The problem with fruit is that it doesn't replicate the sensation that you get when you're eating sweets - by which I mean, the whole pleasure/repitition thing.
So here's one - grapes...I mean, they're small, they're dead sweet, and you can sit there with a bagful, and if you're imagination is strong enough, you can almost persuade yourself they're sweets...
Nature's sweets.
Also, what about pomegrates?
It's not that they're particularly 'healthy', but they're so flipping difficult to eat that you'll get bored and forget that you're hungry.