They should switch to something which is intended to be consumed but calorie sparse like celery.
[video=youtube;Ut6XnpNUaV4]http://www.youtube.com/watch?v=Ut6XnpNUaV4[/video
I do the toilet paper diet. Every other meal is simply a roll of toilet paper. I went from 15-8% body fat with very little effort in about six weeks. Best side benefit is my ass literally wipes itself now.