CHICAGO — The U.S. restaurant industry will end 2012 with a flat number of visits after a slow spring and summer, according to The NPD Group.

The NPG Group said the summer ended on a weaker note than it started with visits flat compared with the same period of the previous year. Visits were up 2% in August but were down in September. Overall, NPD predicts the industry will end 2012 with visits flat and spending up 2%.

“While the restaurant industry basically recovered from last year’s traffic declines, a sluggish economy and continuing cost consciousness on the part of consumers kept the industry stable but not growing,” said Bonnie Riggs, NPD restaurant industry analyst. “The current economic environment and consumer mindset may be longer term than we first thought, and the industry will need to adjust accordingly. There are still growth opportunities in the industry; it’s a matter of identifying the opportunities and as always meeting consumers’ needs and wants.”

Consumers frequented quick-service restaurants the most often, giving the segment traffic gains of 1%. Q.S.R. coffee/donut/bagel, fast casual, retail and Mexican chain concepts all did well during the summer. Q.S.R. hamburger concepts reported flat visits during the summer quarter.

Visits to full-service midscale/family dining restaurants declined 2% during the summer, and casual dining segments had declines of 3%. Declines for supper visits may be attributed to the price disparity between a casual dining and Q.S.R. check, unemployment and consumer cutbacks.

None of the restaurant segments experienced growth during the supper day part. Visit gains at breakfast, lunch and p.m. snacks were all to Q.S.R. restaurants.