Rings right to me. When I'm buried deep in research papers, I don't remember to be hungry (doesn't work for thinking, only for reading-guided learning). Though after a day or so of not eating anything, the mind goes noticeably stupider. I understand that the problem for some people is not that they suffer from hunger, and so can't focus on work, but that lack of food weakens then, even if the distracting effect of hunger is lifted by other means.

The video game diet works for me as well.