Ignorance is not bliss when eating out:

The Food Commission has published a report, Ignorance is not bliss when eating out, which provides evidence of the need for nutritional labelling of fast food menus. If consumers are able to easily view information on fat, salt, sugar and calorie content of meals, they will be able to make healthier choices.

Ignorance is not bliss when eating out: The need for nutrition labelling at fast food and other chain restaurants by Anna Glayzer and Jessica Mitchell, 2008.