Sincerely I'm curious about whose writing led the yukkuri-eating-bacon fashion. I always thought bacon is not Mister Sweet Sweet and often has salt overdose.
The ones portrayed are generally the thick sliced ones. Japanese bacon is closer to cured ham in texture (and it's pre-cooked) and I don't feel it was that salty compared to American bacon. Things in Japan generally have a lot less salt unless it's miso-based.
Also pet yukkuris can be fed normal food, not just sweets. Yukkuris prefer sweets as it's the "best", but they're generally depicted as omnivores. (they eat bugs, grass, nuts, etc in a lot of stories)