In January, economists warned that customers would spend less at places like fast food chains like increase in inflation increases the prices of necessities – and earnings reports released this week indicate that these predictions may have come true.

McDonald's, Starbucks, Pizza HutAND KFC all reported lower-than-expected sales this week.

“It's clear that everyone is fighting for fewer customers or customers who certainly visit less often, and we have to make sure that we have that mentality of street battles to win, (regardless of) the context around us,” the CFO of McDonald's Ian Borden. said on the company's earnings call Tuesday.

Connected: McDonald's CFO says company is testing bigger burgers in 'select' markets this year – Here's why

^{McDonald's logo. (Photo by Paul Weaver/SOPA Images/LightRocket via Getty Images)}

McDonald's saw same-store sales rise 2.5% in the U.S. last quarter, from January to March, which was slightly below expectations of 2.55% growth and well below the fast food chain's 12.6% growth in the same period last year.

Connected: McDonald's CEO says 'affordability' is on the way as company struggles through falling sales

All other companies reported declines in the same category. Same-store sales at Starbucks fell 3% in the US, its first decline in that category in almost three yearswhile Pizza Hut and KFC saw same-store declines of 7% and 2% respectively.

Income reports were weaker how much the analysts EXPECTEDwhich may be due to inflation and higher prices. McDonald's increased menu prices by 10% last year.

or Restaurant business analysis of McDonald's items in all 50 states shows that the average price of a McDonald's cheeseburger rose 55% in the past three years.

“Eating at home has become more affordable,” McDonald's CEO Chris Kempczinski said in an earlier statement. February call earnings.

Connected: McDonald's made a simple change to a cult-favorite menu item. Now, the sandwich is a $1 billion brand.

Data from a recent one consumer price index ratio supports Kempczinski's statement. of REPORT showed that prices for goods in the “food at home” category rose by 1.2% last year, while prices for food abroad rose by 4.2% over the same period.