McDonald's says its price hikes are putting off some customers

• McDonald's said some customers are more "wary" of its price increases. 
• Execs said that low-income diners are placing smaller orders and eating out less often.
• Diners have been complaining that fast food is no longer cheap.

McDonald's keeps putting up menu prices — and it's putting off some diners.

"We certainly know consumers are more wary or weary of pricing," CFO Ian Borden told investors at the company's earnings call on Monday. CEO Chris Kempczinski said that diners had been placing smaller orders, especially low-income customers.

McDonald's had said at its earnings call in October that its price increases largely hadn't put customers off.