How to Teach a Cat to Graze

Question
I have two indoor cats that have always been fed regulated meals twice a day.  I'd like to teach them to graze so that I might be able to go out of town overnight on business occasionally without having to board them.  I have put a copious amount of food in a bowl for two days as an experiment, and they have gobbled up every crumb.  Already they are showing signs of listlessness and becoming pudgy.  How do you train cats to go from regulated meals to healthy grazing?  Should I be patient and let them adjust over a week or two?  How long do I continue the experiment before accepting they're untrainable grubbers?

Thanks!

Answer
You can easily solve this problem by continuing to feed them timed meals. Check out http://www.fosterandsmith.com
they have cat food dishes with sections in them and you can set the timer so that the lids will open at set intervals (on a 24 hr clock too)
this will save you a lot of hassle