I agree with you Serena, that poor guy at your sisters work.
We're already extra vulnerable toward food, that's how we got fat in the first place.
The guy's probably on doctors orders so as not to die of a heart attack and they do a childish high school prank like tempting him with food all day and then laugh when he tries to work it off.
Perhaps your sister should tell him about http://www.weightloss.com.au
then we can talk him out of listening to the evil tempters at his work place