Del Taco Restaurants Inc. in Lake Forest reported higher revenue and net income in its third quarter compared with the same period last year, but revised some projections downward for its full-year performance and shares fell about 20% in Friday trading to a $473 million market cap.

Shares had trended downward 6% yesterday in after-hours trading; Del Taco reported results after markets closed Thursday.

The fast food chain reported revenue of $111 million and net income of $5.1 million, up 6.3% and 4.1% year-over-year.

It revised full-year revenue projections to between $472 million and $475 million from $470 million to $476 million. Earnings per share are now expected between 52 and 54 cents, down from 52 to 55 cents.

It shaved projections on margins—now 19.5% to 19.8%, from 19.8% to 20.3%—and non-GAAP adjusted earnings before interest, taxes, depreciation and amortization, of $71.5 million to $72.5 million, down from $71.5 million to $73.5 million.

“Costs pressures during the third quarter, driven particularly by food inflation,” spurred the revisions, said Del Taco Chief Executive John Cappasola Jr.

On several metrics “we still expect to deliver our annual guidance.”

Comparable systemwide sales grew 4.1% in the quarter—out-pacing company-run stores’ comps of 3.7%. The chain had 558 locations at the September 12 end of the quarter, with 305 or 55% of those company-run.

It opened two company stores and closed one in the third quarter, and opened two franchised locations.

Del Taco is on pace to open 14 locations in the fourth quarter—12 company-run and two franchised sites.