The U.S. restaurant industry projected that sales will peak past $683 billion in 2014, an increase of 3.6% from 2013, according to a forecast released recently by the National Restaurant Association (NRA).

The projected rise would mark an improvement from the recession-battered years of 2008 and 2009, but lags the industry's boom years in the 1970s, when double-digit annual percentage sales growth rates were not uncommon.

Much of the sales growth is expected from menu price inflation, resulting from operators' efforts to offset higher costs for everything from beef to labor. These account for 2.4% of the sales growth in 2014, according to Hudson Riehle, the NRA's senior vice president of research and knowledge.