As a large man who exercises a lot I do refuse to patronize restaurants that serve tiny portions (unless I'm specifically intending to order multiple small plates for tapas or sushi or something). And you're exaggerating with the "3k calorie meal" thing. That rarely shows up on real restaurant menus. Most of them top out at around half that much for a regular entree and a customer would have to add beverages, appetizers, and dessert to reach 3k.