Laughter Can Stimulate a Dull Appetite - BusinessWeek

MONDAY, April 26 (HealthDay News) -- Laughing can boost the appetite in the same way that exercise does, a finding that could help people eat more when they're sick or depressed, a researcher says.
Those who watched funny videos experienced changes in hormone levels that are linked to greater appetite. The changes are similar to those experienced by people when they exercise moderately.

Laughter Can Stimulate a Dull Appetite BusinessWeek
Laughter 'really is the best medicine' The Hindu
Los Angeles Times (blog)