I keep having to re-learn this lesson: I am not capable of being efficiently productive with stationary (computer) work, if I am hungry. I’ll get things done, but it will take a lot longer.
Tasks that require me to move – walking from point A to point B, [non-food] shopping – are not affected by this, within reasonable limits. Neither, for the most part, are stationary tasks that happen mostly on autopilot, like driving.

Vika,
Back in May 2003 you appear to have posted some food for thought about food for thought in the comments section of a blog entry by George Williams.
http://www.ghw.wordherders.net/archives/000227.html
A neat connection between protein digestion and adequate sleep is made.
I find that I am the same way. I tend to need food/drink strewn about my computer desk in order to be an effective programmer/literatist/editor.