Another tactic:

Does your employer offer health insurance? If they do, I'd be willing to bet that they're interested in keeping down health care costs and we all know that they're skyrocketing these days.
Take the approach of "while these foods may taste good and I'm sure they're popular, it's well known that they are not healthy foods for anyone to be eating on a regular basis (give copies of studies regarding transfats and junk food consumption, if possible)". You could also counter their "hypoglycemia is something you're born with" argument (false) with web articles on how people do actually get it along with the fact that often hypoglycemia becomes diabetes if left untreated for too long and I'm sure they're aware of the health costs involved in caring for diabetics (and if they aren't, you might want to provide some statistics along those lines as well).
If they're interested in controlling costs, it's in their best interest to provide snacks that don't promote health problems in their employees or provoke already existing problems. I'd be willing to bet that you also have at least a couple (if not several) diabetics in your office and those snacks for the most part aren't appropriate for them, either.
Of course, another option, is to organize a boycott of said treats if you think you can convince enough people to do it to get their attention.