Why? I do it all the time. Seems wasteful to just throw the food away. I am not going to take food off someone else's plate to take home but so much of the time I am served huge portions and couldn't possibly eat it all. I won't do it on a sales call, but when taking out my client team members they never seem to mind. My clients just get excited that they are getting a free nice dinner. They know that I am expensing the dinner. Maybe it depends on the industry you work in.