According to a recent MarketWatch report, restaurant companies could be in for a challenging period. The skinny? Consumers are offsetting higher nondiscretionary spending needs by taking advantage of falling grocery prices. At the same time, restaurants are grappling with higher operating costs and market saturation. Economics 101, my friends. Falling demand accompanied by rising production costs spells supersized trouble. And following a string of downbeat restaurant earnings from the sector, there could be more pain to come….