In one study, college students were given one of two menus. One menu featured French fries, chicken nuggets and a baked potato; the other included those same items as well as a salad. The French fries, widely perceived as the least healthful option, were three times as popular with students selecting from the menu that had the salad as they were with the other group.

Its not clear from the article if they also ordered (or intended to order later) the salad (fedora flick: Lone Gunman.)