Nutritional labelling may mean more to consumers than portion sizes, according to a joint study from Norway and the US. Information about portion size may not be a good tool to manipulate food-intake behavior. Consumers’ concept of portion size is associated more with objective measures of food than with personal experience about the amount that would be appropriate to eat. See also http://www.foodnavigator.com/Science-Nutrition/Portion-size-may-not-be-a-good-way-to-curb-obesity-Study?nocount