This database includes a number of US market research reports focused on foodservice - including specific subsections like 'fast-casual restaurants'. These reports are unique in the libraries' resources because they are the only source we have that covers some consumer behavior and attitudes information. There are also reports on particular demographic groups and marketing to these groups.
IBISWorld is your best bet for U.S. industry reports, including one on chain restaurants (you could also look at reports for 'competitor' industries like single-location or fast food restaurants).
D&B Hoovers is most often used for company research, but you can also access industry and or market research reports associated with particular companies.
Statista is a huge collection of statistics covering almost every imaginable topic. They also collect these statistics into market and research reports.
You will need a Columbus Metropolitan Library card to use this database, but you should probably have one anyway! Business directory search can be limited by county + industry and easily downloadable up to 500 records.
Factiva allows you to keyword search (so you could search for 'restaurant' + 'millennials' for instance, to see if anything is being discussed on that front) or you can brows all news stories related to a particular industry or company to see what's happening in your area.