I remember a post by Reggio which was about a child who only ate chicken fingers and about three other items and the child ended up with major health issues one if them being diabetes .... I think I would google this issue and find out the long term effects and then open a dialogue with the parents and give them the information .... Cause they may not realize the long term effects and maybe they can push a little harder. For my own kids if they leave the table with out eating it becomes their next meal. No exceptions !