Research paper
Young LR, Nestle M. The contribution of expanding portion sizes to the US obesity epidemic. American Journal of Public Health. 2002;92(2):246-249. doi:10.2105/ajph.92.2.246. PMID: 11818300. PMCID: PMC1447051.
Why we cite it
Landmark public health paper that documented, with specific measurements, how dramatically marketplace portion sizes had expanded beyond federal standards — providing the empirical foundation for the entire portion size research field. Published in the *American Journal of Public Health*, this paper didn't just assert that portions had grown; Young and Nestle weighed actual marketplace foods and compared them to USDA/FDA standard serving sizes, finding that most exceeded standards by factors of 2 to 8. The specific numbers are memorable and shocking: cookies 700% larger than the USDA standard, pasta servings 480% larger, muffins 333% larger. They also tracked the historical timeline, showing that portion expansion began in the 1970s, accelerated sharply in the 1980s, and paralleled the rise in obesity rates. This paper is the foundational "what happened" evidence that the later meta-analyses in cpi02 (Hollands et al. 2015) and cpi04 (Zlatevska et al. 2014) built upon — those papers quantified the behavioral *effect* of larger portions; this one documented the real-world *scale* of the expansion.