How often do people leave the office at lunch?

This article on the hugely entertaining scamp blog, shows (by way of poll) how often people leave the office at lunchtime in advertising.
The facts speak for themselves. I think people are willing to leave the office at lunch, and those who aren't could be persuaded. There is a poll now on that talks about stress in advertising, the creative professions are often high pressure, maybe we should pitch the NPG as a stress reliever?