CHICAGO – Americans have cut back on dining out the second quarter of this year, especially to fast-food restaurants, according to NPD Group research, The Wall Street Journal reports. Since September 2015, visits to quick-service restaurants advanced each quarter by 2%, but that growth ground to a halt in March, April and May of this year. It’s “a red flag because it’s been an area of growth and it’s 80% of the industry,” said Bonnie Riggs, a restaurant analyst with NPD.

With restaurants being among the first businesses to experience a bump when consumers have money to burn, it’s also one of the first industries to feel the pinch when consumers tighten their belts. With job growth slowing and gas prices inching up slightly, consumers may be watching their pennies more closely. Even visits to fast-casual restaurants, which have experienced consistent growth since 2004, had a downturn last month.

“The next few months are fraught with the potential for consumer distractions, from the political conventions in July to the Olympics in August to the presidential debates this fall,” noted Sharon Zackfia, an analyst with William Blair. “As a result, we would not be surprised to see restaurant trends remain somewhat volatile throughout the summer and potentially into the fall.”

The current economic climate has fast-food executives puzzled and without concrete answers about the future. In May, Todd Penegor, CEO of Wendy’s, said that “the consumer does continue to be cautious,” but he also pointed out it’s “been hard to really pinpoint what’s driving that.”