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.

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The literature on whether varying plate size has an effect on consumption is mixed and contradictory. This meta-analysis of 56 studies from 20 papers shows that varying the size of the container holding food (e.g., plate or bowl) has a substantial effect on amount self-served and/or consumed (Cohen's d 5 .43). More generally, we found a doubling of plate size increased the amount self-served or amount consumed by 41%. Our analysis resolves the various contradictions of past reviews: we found that the plate-size effect had a substantial effect on amount self-served (d 5 .51) and on amount consumed when the portion was self-served (d 5 .70) or manipulated along with (confounded with) plate size (d 5 48). However, plate size had no effect on amount consumed when the portion size was held constant (d 5 .03). Overall, plate size had a stronger effect when participants were unaware that they were participating in a food study (d 5 .76).

Young people are a high risk group for gambling problems and university (college) students fall into that category. Given the high accessibility of gambling in Australia and its association with entertainment, students from overseas countries, particularly those where gambling is restricted or illegal, may be particularly vulnerable. This study examines problem gambling and its correlates among international and domestic university students using a sample of 836 domestic students (286 males; 546 females); and 764 international students (369 males; 396 females) at three Australian universities. Our findings indicate that although most students gamble infrequently, around 5 % of students are problem gamblers, a proportion higher than that in the general adult population. Popular gambling choices include games known to be associated with risk (cards, horse races, sports betting, casino games, and gaming machines) as well as lotto/scratch tickets. Males are more likely to be problem gamblers than females, and almost 10 % of male international students could be classified as problem gamblers. Hierarchical regression analysis showed that male gender, international student status, financial stress, negative affect and frequency of gambling on sports, horses/dogs, table games, casino gaming machines, internet casino games and bingo all significantly predicted problem gambling. Results from this study could inform gambling-education programs in universities as they indicate which groups are more vulnerable and specify which games pose more risk of problem gambling.

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