Food marketing is facing increasing challenges in using portion size
(e.g., “supersizing”) as a marketing tool. Marketers have used portion
size to attract customers and encourage purchase, but social agencies
are expressing concern that larger portion sizes encourage greater
consumption, which can cause excessive consumption and obesity. This
article addresses two questions that are central to this debate: (1) How
much effect does portion size have on consumption? and (2) Are there
limits to this effect? A meta-analytic review reveals that, for a
doubling of portion size, consumption increases by 35% on average.
However, the effect has limits. An extended analysis shows that the
effect of portion size is curvilinear: as portions become increasingly
larger, the effect diminishes. In addition, although the portion-size
effect is widespread and robust across a range of individual and
environmental factors, the analysis shows that it is weaker among
children, women, and overweight individuals, as well as for nonsnack
food items and in contexts in which more attention is given to the food
being eaten. [ABSTRACT FROM AUTHOR]