McDonald's is losing ground to rivals like Burger King with a key customer group

Low-income diners are spending less at McDonald's, Numerator found.

Mario Tama/Getty Images McDonald's is losing sales among low-income diners, new data shows.

Numerator found that sales among low-income customers slipped 2.4% duing the chain's latest quarter.

McDonald's has said that the execution of its latest value menu hampered second-quarter sales.

McDonald's is losing ground to rivals among low-income fast-food diners, according to recent data.

Spending by low-income guests at the Golden Arches declined 2.4% year-over-year during the company's latest quarter, said consumer analytics company Numerator.

The firm defines "low-income guests" as those from households making $40,000 or less a year.

The drop is McDonald's first quarterly decline with low-income guests in the past year and amounts to roughly $310 million in lost sales, Numerator said on Tuesday.

Rival fast-food chain Burger King, meanwhile, notched a 0.3% gain over the same period.

The data is the latest sign that McDonald's is struggling to attract diners, especially in a K-shaped economy.

While the chain long won over price-conscious diners with deals like its buy-one-get-one discount on sandwiches such as the Big Mac, it has had issues rolling out its latest value menu, which focuses on items priced $3 or less, CEO Chris Kempczinski said on an earnings call earlier this month.

"Although we've restored our overall value and affordability leadership, our restaurant-level results show that execution was inconsistent across the system," Kempczinski said.

McDonald's comparable US sales growth slowed to 0.8% during its second quarter, the company said.

Rivals from Burger King to casual dining chain Chili's have posted stronger results while offering their own value menus and deals, Business Insider has reported.