Comparable sales fell 0.4% in the first quarter, according to a statement Wednesday, while analysts were expecting growth of 1.7%. A decline in transactions drove the slide, a reversal from recent quarters in which Chipotle had managed to attract diners even as peers struggled.

Chipotle Mexican Grill Inc. lowered its full-year outlook after quarterly sales declined for the first time in almost five years, suggesting that economic uncertainty is causing diners to pull back on burrito outings.