If you glance around a Taco Bell, you might see a lot of people who are kinda down. Depressed, frowning, quietly and angrily destroying a Crunchwrap Supreme. Well, a new study says that's definitely the norm.

A market research company called BIGinsight surveyed 9,000 fast food customers and asked them how happy they are overall...not with the food, just happy in general. Then they figured out which restaurants have the happiest and saddest customers.

The fast food chains with the happiest overall customers are Arby's, Chick-Fil-A, and Subway.

The fast food chains with the saddest overall customers are McDonald's, Taco Bell, Wendy's, and Burger King.

The survey also connected people's physical health to their favorite fast food restaurants and the results were very similar. Subway had the healthiest customers, McDonald's were least healthy.

(Forbes)