Los Angeles — FAT (Fresh. Authentic. Tasty.) Brands Inc. has opened Fatburger’s first theme park location at Six Flags Great Adventure in Jackson, N.J. The restaurant marks the second Fatburger in the state. “We have been exploring opportunities to make this growth move for some time and are pleased that we are able to make our foray into this space with such a strong partner as Six Flags,” says Jake Berchtold, chief operating officer of FAT Brands’ fast casual division. The first Fatburger opened in Los Angeles 70 years ago, …