RFID for Veggies

Some RFIDs, the real cheap and small ones, just contain a fixed number. They are getting small enough so you can swallow them accidentally.
The idea is a kit for concerned mothers. It consists of a bag of tiny RFIDs wrapped in chew-resistant plastic capsules and a RFID reader. Mothers read the RFIDs, note their stored numbers, and then use them to lace the hated (by the kids), but healthy (according to tabloids) vegetables. If there is doubt that the kids ate their vegetables they are easily scanned with the reader. Mom can tell exactly when they lied. After a few successful uses of the "lie detector" kids will become honest.
Note 1: I will never force kids to eat their veggies because some stupid tabloid medical column its healthy, but a few bucks could put my conscience to rest about selling the kit.
Note 2: Leftover RFIDs can be mounted on slippers to check if the dog ate them, that lying bastard needs a lesson too.