Dunkin' Donut's CEO says America has too many restaurants -- and that's a bad sign for chains (DNKN)

Erin/Flickr There's an obvious answer to why the restaurant industry is struggling in the US. "Not many categories are truly growing," Dunkin' Brands CEO Nigel Travis told Business Insider. "The country is probably over-restauranted," Travis continued. "Over-restauranted" means that there are simply more restaurants in the US than customers care to visit. Basically, the supply of restaurants opening outpaces the demand— and it's resulting in slumping sales. Restaurant customer traffic has been...