updated 04/06/2011 AT 6:00 PM ET
•originally published 04/06/2011 AT 6:30 PM ET
Matthew Morrison is known for his ripped physique – but how does he do it?
The Glee star, 32, who shows off his washboard abs in a series of beach photos in a recent issue of Details, also reveals a slightly unusual diet secret.
For three days before the photo shoot, the actor, who plays McKinley High’s glee club leader Will Schuester, ate nothing but sweet potatoes.