Reason 191: He eats bananas to grow his beard.
“My big problem is beard… That’s the problem. This beard [points to his face] this’s costed me… lot of effort is going into this! The beard is the problem cause I’m playing an unshaven character , as I was there I need, you know, whatever like 5 or 6 days after that… of concentrated beard-growing. And ahm… I need to eat a lot of bananas. Potassium is very important.” Hugh Laurie (after playing other role while he was on House and he had to shave.)
Source: http://www.youtube.com/watch?v=szO3wT2Yhi0