Eating healthier and cutting back on fast-food meals are popular topics. And we’re ordering more hamburgers too.

Customers ordered 9 billion burgers in 2014, an increase of about 3 percent from the year before, Chicago-based market researcher NPD Group says in a report released Wednesday.

At the same time, sandwich orders at restaurants and foodservice outlets fell by 2 percent last year to 12.4 billion. And orders for grilled chicken sandwiches, which NPD says is the hamburger’s chief rival, fell 9 percent last year to 1.3 billion.

“The success of burgers in 2014 was a combination of factors,” says Bonnie Riggs, NPD’s restaurant industry analyst. “Quick service restaurant chains launched new burger items, casual dining restaurants added more burger items to the menu to offset higher beef costs, and Americans simply love their burgers.”

So maybe Shake Shack is onto something. The hamburger and milkshake palace, which opened its first Chicago restaurant last fall, on Wednesday raised the project price range for its IPO.