Research paper
Zlatevska N, Dubelaar C, Holden SS. Sizing up the effect of portion size on consumption: a meta-analytic review. Journal of Marketing. 2014;78(3):140-154. doi:10.1509/jm.12.0303.
Why we cite it
Meta-analytic review published in the *Journal of Marketing* — one of the top marketing journals — that quantifies the portion size effect from a consumer behavior perspective. While the Cochrane review (cpi02, Hollands et al. 2015) approached portion size from a public health standpoint, this paper comes from marketing science, bringing methodological tools like meta-regression and moderator analysis to explain *when* and *for whom* the effect is stronger or weaker. The headline finding — doubling portion size increases consumption by 35% on average — provides a concrete, memorable number for the project. The curvilinear finding is practically important: the portion size effect has diminishing returns at extreme sizes, meaning people don't simply eat proportionally more from ever-larger portions. The moderator analysis reveals counterintuitive patterns: the effect is *weaker* among overweight individuals and women, and *stronger* when people eat inattentively — the last point directly supporting mindful eating as a countermeasure.