Is Barcelona "hard" for the skinny student? Absolutely. You will face hunger pangs, the frustration of seeing tourists splash cash on paella while you eat flautas from Mercadona, and the exhaustion of a part-time schedule that leaves no room for rest.
The "hard" becomes manageable when you discover El Corte Inglés basement bakeries at 9 PM, where fresh bread is sold for 50 cents.