Fatter is dumber?
... or at least it seems to be in lab mice. Researchers at Yale's medical school have discovered that mice who take tests while hungry do significantly better than sated mice. They process information faster, they retain it longer; basically, they're smarter. The culprit seems to be the hormone grellin, produced by the lining of the stomach when empty. It binds not only to that part of the brain which registers hunger (the hypothalamus) but to the researchers' surprise, to the memory and learning centers of the brain, as well (the hippocampus).
"It makes sense," researcher Tamas Horvath says. "When you are hungry, you need to focus your entire system on finding food in the environment." Many biologists believe that this is how human intelligence formed, too: out of munchies-stimulated necessity. (You might refer to our blog on how much being a Neanderthal sucked.) This raises some interesting questions: is there any relation between the increasing girth of our schoolkids and their decreasing test scores? (Someone's going to have to skip lunch in order to find out.)
The researchers do offer some practical advice (for humans) based on their mouse tests: when taking a test or doing an interview, don't load up on "brain food" before you go in. Be a little hungry throughout, and maintain that level of hunger with a light snack here and there. (I know if I'm too hungry, I get grumpier, not smarter.) Can you imagine taking the SAT right after loading up on Thanksgiving turkey? Me, neither.