I had a similar problem with a colleague. She is very overweight and would make comments about the size of my lunchbox etc etc. She watched me like a hawk when I was eating. I would smile nicely back at her with every comment. Finally when we were alone, she broke down and told me how unhappy she was being fat. Anyway, six months later.... she got a lapband too :-) I have found the worst people are the overweight ones...