Restaurants are paying more for ingredients, yet a recent survey shows they’re reluctant to equally raise menu prices, choosing to watch margins shrink instead.

National Restaurant News reports commodity prices were three percent higher in 2012 with dry weather this summer increasing the price of U.S. crops. A November survey of 35 chain restaurants by SpenDifference LLC found respondents only raised menu prices by an average of 1.2 percent midway through the fourth quarter.

Survey results from the previous year found restaurants raised prices by an average of 1.5 percent. In that same year, their food costs increased by roughly 1.7 percent with some commodities, such as beef and dairy, increasing by over five percent.

The outlook for 2013 isn’t likely to improve. Reuters reports the Food and Agriculture Organization expects food prices to remain high for the year and low stocks may spur sharp price increases. More trouble could arise if we have a third consecutive year of drought.

Restaurant chains in previous years have raised prices on select menu items, however this year a majority of the respondents (63%) said they were choosing to raise prices on all of their menu items. Only 23 percent were raising prices on select items in 2012.

While 71 percent in the survey increased prices in some aspect, 26 percent of restaurants reduced portion sizes. A majority of restaurants also renegotiated purchasing contracts (63 percent) or promoted lower food cost menu items (66 percent).